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1

Zhang, Lu. "TADF process in blended organic luminescent material". HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/340.

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Organic light-emitting diode (OLED) devices have been applied in the fields of display and solid-state lighting. In addition to phosphorescent OLEDs using heavy transition metals, a new approach of harvesting both singlet and triplet excitons generated in the OLED device by using pure organic materials has drawn a lot of attentions in recent years. It is thermally activated delayed fluorescence (TADF) process, which makes it possible to obtain potential 100% internal quantum efficiency (IQE);TADF is a process existing in certain organic materials with small singlet-triplet exchange energy (EST), which is generally observed in the molecules with weak-coupled electron-donating (D) group and electron-accepting (A) group. Individual molecule containing D/A, which is named intramolecular exciplex, or intermolecular exciplex with D/A on separated molecules, can fulfill this requirement. Although at present the intramolecular exciplex attracts considerable research interests, it takes a lot of efforts to design an individual molecule with high fluorescent quantum yield as well as small EST. Intermolecular exciplex, which is achieved by physically blending individual D and A molecules with appropriate selection from present materials, has excellent performance comparable to the phosphorescent emitter.;In this work, we studied the TADF process in an intermolecular exciplex and its application in highly efficient OLED devices. By doping electron-donating material tris(4-carbazoyl-9-ylphenyl)amine (TCTA) with electron-accepting material 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (Tm3PyBPZ), an exciplex with a green emission around 514 nm was demonstrated. The time-resolved photoluminescence of the exciplex under different temperatures from 12 K to 300 K demonstrated the existence of temperature-dependent delayed fluorescence. By applying this exciplex as the emissive layer, a highly efficient all-fluorescent organic lighting emitting diode with maximum efficiencies of 13.1% and 53.4 lm/W was realized with an extremely low turn-on voltage of only 2.4 V. The efficiencies of the device have outperformed conventional fluorescent OLED devices due to the contribution of triplet excitons. By doping this exciplex with other conventional green or yellow fluorescent dopants, we observed that the performances of these dopants also surpass the limitation of conventional fluorescent OLED (5̃ % external quantum efficiency)
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2

Gutierrez, Gregory D. (Gregory Daniel). "Luminescent organic materials and their application in solar technologies". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/117933.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2016.
Cataloged from PDF version of thesis. Vita.
Includes bibliographical references.
In Chapter 1, we begin with a brief introduction to the principles of photoluminescence from organic materials and the luminescent solar concentrator (LSC). In Chapter 2, we describe the red phosphorescence from a class of four structurally simple benzo[2,1,3]thiadiazoles in cyclohexane. The photophysical properties of these molecules are presented along with a computational analysis of their electronic excited states. Chapter 3 discusses the development and evaluation of an efficient, low-reabsorbing luminescent solar concentrator (LSC) that employs two 7r-conjugated polymers as surrogate absorbers for a minority amount of the perylene bisimide Lumogen F Red 305. We developed a small LSC wherein a mixture of the two polymers act as both the host layer and antennae for a 1.5 wt% loading of Lumogen F Red 305. A Monte Carlo simulation predicts the LSC to possess high edge optical efficiencies and concentration factors on larger, commercially relevant scales. Efforts toward an efficient energy transfer cascade between three 7r-conjugated polymers in poly(methyl methacrylate) (PMMA) are also discussed. Chapter 4 describes an LSC that utilizes a deoxygenated liquid perfluorocarbon (PFC) as the host for a strongly fluorescent perfluoroalkylated thieno[3,4-b]pyrazine between two slabs of PMMA. In the event the luminophore photodegrades after prolonged exposure to sunlight, the luminescent layer can be easily replaced with new solution. Additionally, we demonstrate that the relatively low refractive indices of PFCs causes the luminophore's emission to efficiently couple into the PMMA slabs, where no reabsorption processes can undermine the efficiency of the LSC. In Chapter 5, we present progress toward iptycene-functionalized naphthazarins intended for the development of solid-state luminescent or redox-active metallopolymers.
by Gregory D. Gutierrez.
Ph. D.
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3

Zheng, Yonghao. "New luminescent organic and organometallic materials for OLED applications". Thesis, Durham University, 2011. http://etheses.dur.ac.uk/830/.

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The design, synthesis and photophysics is presented for a new series of fluorescent carbazole-2,5-diphenyl-1,3,4-oxadiazole dyad molecules and in which the topology and electronic properties are systematically varied by chemical modification. Cyclic voltammetric data, HOMO-LUMO calculations, and X-ray crystallographic analyses are also presented. Our study sheds new light on designing ambipolar molecules and we demonstrate a strategy for precisely tuning the singlet and triplet levels in charge transfer molecules. A family of new 2,5-diphenyl-1,3,4-oxadiazole (OXDs) derivatives bearing ortho-alkyl substituents on one of the phenyl rings is reported. The reactions of these OXDs with IrCl3 under standard cyclometalating conditions did not give the usual μ-dichloro bridged diiridium OXDs complexes. Instead, novel diiridium complexes and monoiridium complexes were isolated and characterised by X-ray crystallography. It is proposed that the unusual structures arise due to the ortho-alkyl substituents leading to a substantial twisting of part of the OXDs system which, for steric reasons, changes the normal course of the metal-ligand coordination reactions. A new high triplet host polymer was synthesised and characterised. Photophysical studies and device data are presented. The triplet energy of this polymer is 2.73 eV. Also, the unoptimised device efficiency (device architecture: ITO/PEDOT:PSS/8% 145 and 40 wt% OXD-7 doped in polymer 133/Ba:Al) is 4.5 cd/A. Our study sheds new light on designing high triplet polymers and we demonstrate a strategy for possessing a high triplet level in a polymer by interrupting the conjugation on the polymer backbone.
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4

Correia, Sandra Filipa Henriques. "Organic-inorganic hybrid materials for green photonics: luminescent solar concentrators". Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/17407.

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Doutoramento em Física
Luminescent solar concentrators are inexpensive devices that aim to increase the efficiency of photovoltaic cells and promote the urban integration of photovoltaic devices, with unprecedented possibilities of energy harvesting through the façade of buildings, urban furniture or wearable fabrics. Generally, they consist of a transparent matrix coated or doped with active optical centres that absorb the incident solar radiation, which is re-emitted at a specific wavelength and transferred by total internal reflection to the edges where the photovoltaic cells are located. The main objective of this work is the production of luminescent solar concentrators whose optically active layer is based on organic-inorganic hybrid materials doped with europium ions or organic dyes, in particular, Rhodamine 6G and Rhodamine 800. Rhodamine 800, as opposed to europium ions and Rhodamine 6G which emit in the visible range, emits in the near infrared (NIR) range, which is an advantage for crystalline Si-based photovoltaic cells, whose efficiency is greater in the NIR. In this work, although the luminescent solar concentrators with planar geometry are addressed, the main focus is the use cylindrical geometry. The use of this type of geometry allows the effect of concentration to be higher relative to the planar geometry, since the ratio between the exposed area and the area of the edges is increased. The cylindrical geometry is exploited by producing luminescent solar concentrators based on polymer optical fibre (plastic) where the optically active layer is on the outside (as a coating) or inside (as a filling in the hollow core) of the optical fibre. Furthermore, the possibility of increasing the exposed area was also dealt with the production of bundles of luminescent solar concentrators in which the plastic optical fibres are placed side by side and, also, by fabricating luminescent solar concentrators with length in the metre scale.
Os concentradores solares luminescentes são dispositivos de baixo custo que têm como objetivo aumentar a eficiência de células fotovoltaicas e promover a integração de dispositivos fotovoltaicos em elementos do dia-a-dia, tornando possível a captura de energia solar, através da fachada de edifícios, mobiliário urbano ou em têxteis. Geralmente, consistem numa matriz transparente coberta ou dopada com centros óticos ativos, capazes de absorver a radiação solar incidente e reemiti-la com um comprimento de onda específico que será transportada, através de reflexão interna total, para as extremidades da matriz onde se encontra(m) a(s) célula(s) fotovoltaica(s). O principal objetivo deste trabalho consiste na produção de concentradores solares luminescentes cuja camada ótica ativa é baseada em materiais híbridos orgânicos-inorgânicos dopados com iões lantanídeos (európio, Eu3+) ou corantes orgânicos, nomeadamente, Rodamina 6G e Rodamina 800. A Rodamina 800, ao contrário dos iões de európio e da Rodamina 6G que emitem na gama do visível, emite na região espetral do infravermelho próximo (NIR), que se revela uma vantagem quando a célula fotovoltaica em uso é composta de silício cristalino, cuja gama de maior eficiência é no NIR. Neste trabalho, apesar de serem abordados concentradores solares luminescentes com geometria planar, o principal foco é a utilização da geometria cilíndrica. Este tipo de geometria permite que o efeito de concentração seja superior, relativamente à geometria planar, uma vez que a razão entre a área exposta e a área das extremidades é aumentada. A geometria cilíndrica é explorada, através da produção de concentradores solares luminescentes com base em fibra ótica polimérica (plástica) em que a camada ótica ativa se encontra no exterior (como um revestimento) ou no interior (como um preenchimento do núcleo oco). Além disso, a possibilidade de aumentar a área exposta foi, também, abordada com o fabrico de uma matriz de concentradores solares luminescentes colocados lado a lado e, também, com o fabrico de concentradores solares luminescentes na escala do metro.
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5

Manavbasi, Alp. "Development of new inorganic luminescent materials by organic-metal complex route". abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3387812.

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6

Atoini, Youssef. "New luminescent hybrid materials : synthesis and properties". Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF004/document.

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L'objectif de cette thèse est la synthèse, la caractérisation et l'étude de complexes métalliquesluminescents, en particulier de Pt (II), leurs propriétés d'agrégation en solution, mais également dansun espace confiné ainsi qu’en surface. L'incorporation de complexes de métaux de transition dans lastructure poreuse, et ainsi que leur dépôt à la surface de nanoparticules et dans un cadre métalloorganique(MOF), par greffage post-synthétique, ont été étudiés. Sont également étudiés lacorrélation entre les propriétés de films d’une série de complexes de Pt(II) avec leur morphologie,leur mobilité électronique et la simulation de leur structure auto-assemblée par diffraction auxrayons-X. Les propriétés de luminescence de complexes amphiphiles de Pt(II) sont améliorées àl’intérieur de nanoparticules de silice mesoporeuse par la création d’un d’espace confiné. Un effetsimilaire est observé par le dépôt de complexes de Pt(II) fonctionnalisés sur une surface denanoparticules d’or. La luminescence d’un cadre organométallique a été modifiée par greffage postsynthétiquede complexes d’Ir(III) et de Pt(II)
The aim of this thesis is the synthesis, characterization and investigation of luminescent metalcomplexes, and in particular of Pt(II) compounds, their aggregation properties in solution but inconfined space as well. The incorporation of transition metal complexes in porous structure, and inparticular in a metal-organic framework (MOF), by post-synthesis grafting, have been investigated.Luminescence properties of amphiphilic Pt(II) complexes were enhanced inside mesoporous silicananoparticles by the creation of a confined space. Similar effect is observed by deposition offunctionalized Pt(II) complexes on gold nanoparticles surface. Luminescence of metal organicframework was tuned by post-synthetic grafting of Ir(III) and Pt(II) complexes
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7

Bellucci, Luca. "Thermometers at the Nanoscale: a Molecular Approach to Design and Develop Functional Lanthanoid-based Luminescent Materials". Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422334.

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The present work is devoted to the development of lanthanoid-based luminescent thermometers and to the study of the correlations between the thermometric properties and the different building blocks composing the systems. In particular, using rare earth cations, b-diketones (H(b-dike)= dibenzoylmethane, Hdbm; benzoyltrifluoroacetone, Hbta; hexafluoroacetylacetone, Hhfac; thenoyltrifluoroacetone, Htta), and divergent ligands (4,4’-bipyridine, bipy; 4,4’-bipyridine-N-oxide, bipyMO; pyrazine-N-oxide, pyrzMO; 2,5-dihydroxy-1,4-dicarboxylate, H2DHT2-) we prepared molecular systems with different dimensionality: i) dinuclear complexes (0D), ii) Coordination Polymers (CPs, 1D), and Metal-Organic Frameworks (MOFs, 3D). We started with europium β-dike dinuclear compounds with molecular formula [Eu2(β-dyke)6(L-MO)x] (x=3 for hfac, x=2 for dbm, bta, and tta). Substituting the hfac -CF3 groups with phenyl rings (one in bta, two in dbm) or with a thienyl ring (tta) the β-dike electronic and steric properties were modulated. Conversely, the different steric hindrance of bipyMO and pyrzMO influenced the spatial disposition of the β-dike ligands and the inter- and intra-molecular interactions. In the -50 ÷ 100 °C temperature range, the complexes showed relative thermal sensitivity (Sr) values higher than 1 (generally assumed as a quality criterion for these thermometers) that depended on the nature of both the β-dike and L-MO ligands. The β-diketonates influenced Sr values, thermal operative range, and photostability of the system, while pyrzMO-containing compounds showed improved performances (Sr maximum from 4.6 to 8.1 % °C-1 depending on the β-dike ligand) compared to that based on bipyMO (Sr maximum from 3.4 to 5.1 % °C-1). In the second part, a series of ratiometric Eu3+/ Tb3+ luminescent thermometers were obtained by mixing different quantities of the two homometallic [Ln(hfac)3(bipy)]n 1D-CPs (Ln3+= Eu3+ and Tb3+) in spectroscopically inert KBr. Here, we studied the effect of the relative metal amounts and of the excitation wavelength on the Sr. For all the samples, Sr values almost independent from the Tb/Eu molar ratio and the excitation wavelength were found between -190 and 110 °C. Each sample showed a peculiar temperature-dependent emission colour, from green to red, that was exploited to develop colour-coded thermometers able to distinguish temperature intervals in the order of 10/ 20 °C. Then we developed a mild-condition synthetic procedure to obtain single crystal to single crystal post-synthesis modifications of the 3D-MOF [Eu2(H2DHT)3(DMF)4]∙2DMF (DMF= N,N-dimethylformamide) to substitute DMF in the channels with different organic molecules (i.e. CHCl3, imidazole, pyridine, and tetrahydrofuran) and to study the Sr modulation. Depending on the guest molecule, the temperature at which Sr reaches the maximum and its value varied from 2.5 at -90 °C to 4.2 % °C-1 at -10 °C. Molecular compounds like complexes, CPs and MOFs are ideal systems to study the correlations between structure, composition (in the meaning of molecular functionalization) and functional properties because they can be easily modified through chemical processes. Nevertheless, to exploit the unique properties of these compounds in commonly used tools and instruments they need to be integrated into a device. Surface functionalization is a recurrent way to achieve this target. However, maintaining the control on the arrangement of the various building blocks and characterize the functionalized surface is not straightforward, so that the development of “ad hoc” synthetic protocols and methods is required. In this context, we developed a general procedure for surface functionalization. We exploited the reactivity of lanthanoid N,N-dialkylcarbamate complexes to create an ordered Eu3+-Tb3+ heterobimetallic sequence grafted on amorphous silica using terephthalic acid as divergent ligand to connect the two Ln3+ ions. Photoluminescence was here used to determine the spatial disposition of the two metal ions on silica. In particular, Tb3+-to-Eu3+ energy transfer was used as molecular ruler to study the Ln3+ ions spatial distribution and intermetal distances that allow us to obtain data supporting the formation of the desired sequence.
Questo lavoro è volto allo sviluppo di termometri molecolari a base di ioni lantanoidei ed allo studio delle correlazioni tra proprietà termometriche ed i diversi building blocks che compongono i sistemi. In particolare, usando cationi lantanoidei, β-dichetoni (H(β-dike)= dibenzoilmetano, Hdbm; benzoiltrifluoroacetone, Hbta; esafluoroacetilacetone, Hhfac; tenoiltrifluoroacetone, Htta), e leganti divergenti (4,4’-bipiridina, bipy; 4,4’-bipiridina-N-ossido, bipyMO; pirazina-N-ossido, pyrzMO; 2,5-diidrossi-1,4-dicarbossilato, H2DHT2-) sono stati preparati sistemi molecolari con diversa dimensionalità: i) complessi dinucleari (0D), polimeri di coordinazione (CPs, 1D) e Metal Organic Frameworks (MOFs, 3D). Nei complessi dinucleari di europio [Eu2(β-dike)6(L-MO)x] (x=3 per hfac, x=2 per dbm, bta, and tta) le proprietà elettroniche e steriche del β-dichetonato sono state modulate sostituendo i gruppi -CF3 di hfac con anelli fenilici (uno nel bta, due nel dbm) o con un anello tienilico (tta). Il diverso ingombro sterico dei leganti bipyMO e pyrzMO influenzarono invece la disposizione spaziale dei leganti β-dichetonato e le loro interazioni inter- ed intra-molecolari. I complessi mostrarono valori di sensibilità termica relativa (Sr) maggiori di 1 (valore generalmente usato come criterio di qualità per questi termometri) dipendenti dalla natura dei leganti β-dike e L-MO nell’intervallo di temperatura -50 ÷ 100 °C. I leganti β-dichetonato influenzarono i valori di Sr, l’intervallo applicativo di temperature e la fotostabilità dei complessi. I composti contenenti pyrzMO mostrarono performances migliori (Sr massimo da 4.6 a 8.1 % °C-1 a seconda del β-dike) rispetto agli analoghi con bipyMO (Sr massimo da 3.4 a 5.1 % °C-1). Successivamente è stata ottenuta una serie di termometri luminescenti raziometrici a base di Eu3+ e Tb3+ miscelando diverse quantità dei due polimeri di coordinazione 1D [Ln(hfac)3(bipy)]n (Ln3+= Eu3+ e Tb3+) in KBr (inerte dal punto di vista spettroscopico). In questo caso è stato studiato l’effetto su Sr della quantità relativa dei due ioni metallici e della lunghezza d’onda di eccitazione nell’intervallo -190 ÷ 110 °C. Per tutti i campioni i valori di Sr risultarono non influenzati dal rapporto molare Tb/Eu e dalla lunghezza d’onda di eccitazione. Ciascun campione mostrò un peculiare colore emesso (dal verde al rosso) in funzione della temperatura. Ciò è stato sfruttato per sviluppare termometri basati su codici di colori capaci di distinguere intervalli di temperatura di 10/ 20 °C. È stata inoltre sviluppata una procedura basata su condizioni blande per attuare la modifica post-sintetica da cristallo singolo a cristallo singolo del MOF [Eu2(H2DHT)3(DMF)4]∙2DMF (DMF= N,N-dimetilformamide) sostituendo la DMF nei canali con diverse molecole (CHCl3, imidazolo, piridina e tetraidrofurano) per studiare la modulazione di Sr. A seconda della molecola ospitata, la temperatura alla quale si raggiunge il massimo di Sr e il suo valore variarono da 2.5 a -90 °C a 4.2 % °C-1 a -10 °C. Composti molecolari come complessi, CPs e MOFs sono ideali per lo studio delle correlazioni tra struttura, composizione (nel senso di funzionalizzazione molecolare) e proprietà funzionali in quanto facilmente modificabili tramite processi chimici. Tuttavia, è necessario integrare questi sistemi in dispositivi per sfruttare le loro proprietà in strumenti di uso comune. La funzionalizzazione di superfici è una procedura comunemente usata per questo scopo. In questo caso tuttavia, non è semplice mantenere il controllo sulla disposizione dei vari building blocks e caratterizzare la superficie funzionalizzata così che è fondamentale sviluppare un adeguato protocollo sintetico. In questo contesto, è stata messa a punto una procedura sintetica per la funzionalizzazione di superfici. Per questo scopo è stata sfruttata la reattività degli N,N-dialchilcarbammati lantanoidei per creare una sequenza eterobimetallica Eu3+-Tb3+ ordinata aggraffata su silice amorfa, usando l’acido tereftalico come legante divergente per connettere i due centri metallici. La fotoluminescenza è stata qui utilizzata per determinare la distribuzione spaziale dei due ioni metallici sulla silice. In particolare, fenomeni di trasferimento energetico dal Tb3+ all’Eu3+ sono stati usati come righello molecolare per determinare la distribuzione e le distanze intermetalliche ottenendo dati a supporto della formazione della sequenza desiderata.
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8

Narikiyo, Hayato. "Development of Functional Materials Based on Polyhedral Oligomeric Silsesquioxane with Flexible Side-Chains". Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263688.

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付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム
京都大学
新制・課程博士
博士(工学)
甲第23227号
工博第4871号
京都大学大学院工学研究科高分子化学専攻
(主査)教授 田中 一生, 教授 秋吉 一成, 教授 古賀 毅
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DGAM
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9

Lahoud, Marcelo Galindo [UNESP]. "Síntese e investigação da potencialidade de aplicação como material molecular de espécies discretas e Metal Organic Frameworks (MOFs) baseados em íons terras raras". Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143479.

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Este trabalho é dividido em duas partes, na primeira parte foi caracterizado o complexo [Ln(keto)3(H2O)] (Ln = Gd, Eu) por espectroscopia vibracional no infravermelho, analise elementar e otimização da geometria por método DFT. Mas o foco central foram os estudos das propriedades luminescente no intervalo de 12 – 300 K. O espectro de emissão do [Eu(keto)3(H2O)] revela uma forte dependência com a temperatura, bem ilustrada pelo não usual deslocamento amplo para o azul de (17 cm1) da transição 5D07F0 quando a temperatura é elevada de 12 a 300 K. A diferença aritmética entre os espectros de absorção do [Eu(keto)3(H2O)] com o do [Gd(keto)3(H2O)] indicou a presença de uma banda de transferência de carga do ligante para o metal (LMCT) (320-370 nm). A partir da fosforescência do [Gd(keto)3(H2O)] a energia dos estados de tripleto relacionada ao Keto foi determinada mostrando uma grande sobreposição com os níveis intra-4f6 e um forte acoplamento elétron-fônon. A alta ressonância entre o nível LMCT e estados tripletos e os níveis do Eu3+ leva a uma forte dependência do valor do tempo de vida da 5D0, típico da presença de processos de transferência de energia operativos. A segunda parte desse trabalho compreendeu na síntese, caracterização e estudos das propriedades luminescente e magnéticas de uma MOF inédito de formula [Eu2(Btec)1,5(H2O)]n. A MOF foi sintetizada por via hidrotermal e caracterizado por DRX de monocristal e pó, espectroscopia vibracional no infravermelho, reflectância difusa, analise elementar, analise térmica, microscopia eletrônica de varredura e fisissorção de N2. O composto apresentou boa estabilidade térmica no entanto mostrou-se ter baixa porosidade. A MOF apresentou emissão na região do vermelho com elevado rendimento quântico de emissão, mostrando que o ligante é um bom sensibilizador nesse sistema. As emissões dos íons Eu3+ mostraram-se ser uma sonda espectroscópica, contribuindo na elucidação da estrutura. Foi observado uma dependência térmica em relação à intensidade das transições originárias do nível 7F1, em especial a transição 7F15D1. Além disso, as transições intraconfiguracionais 4f-4f mostram ter uma boa fotoestabilidade. Resultados de susceptibilidade magnética mostram íons Eu3+ magneticamente afastados e portanto os torna uma fraca probe estrutural.
This work is divided into two parts, the first part was characterized the complex [Ln(keto)3(H2O)] (Ln = Gd, Eu) by infrared spectroscopy, elemental analysis and geometry optimization by DFT method. But the central focus was the study of luminescent properties in the 12-300 K interval. The emission spectra of [Eu(keto)3(H2O)] reveal a strong dependence with the temperature, well-illustrated by an unusual large blue-shift (17 cm1) of the 5D07F0 transition as the temperature is raised from 12 to 300 K. The arithmetic difference between the absorption spectrum of [Eu(keto)3(H2O)] with that of [Gd(keto)3(H2O)] pointed out the presence of a ligand-to-metal charge transfer (LMCT) band (320-370 nm). From the [Gd(keto)3(H2O)] phosphorescence the energy of the keto-related triplet states was determined showing a large overlap with the intra-4f 6 levels and a strong electron-phonon coupling. The high-resonance between the LMCT and triplet states and the Eu3+ levels leads to a strong dependence of the 5D0 lifetime value, typical of the presence of operative energy transfer processes. The second part of this work included in the synthesis, characterization and study of luminescence and magnetic properties of a novel MOF formula [Eu2(Btec)1,5(H2O)]n. The MOF was synthesized by way hydrothermal and characterized by XRD of single crystal and powder, infrared spectroscopy, diffuse reflectance, elemental analysis, thermal analysis, scanning electron microscopy and N2 physisorption. Compound demonstrated good thermal stability however proved to have low porosity. MOF showed emission in the red region with a high emission quantum yield, showing that the ligand is a good sensitizer in the system. The emission of Eu3+ ions proved to be a spectroscopic probe, contributing to the elucidation of the structure. A thermal dependence was observed in relation to the intensity of originating 7F1 level transitions, in particular the 7F15D1 transition. Furthermore, the 4f-4f transitions intraconfigurational shown to have a good photostability. Magnetic susceptibility results show Eu3+ ions separated magnetically and thus makes a weak probe structure.
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10

Miller, Paul Francis. "Luminescence studies of molecular materials". Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342250.

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11

Sano, Takeshi. "Charge transport and luminescence control in organic and conjugated materials". Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620333.

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12

RIGODANZA, FRANCESCO. "Photoluminescent materials: from organic molecules to nanomaterials". Doctoral thesis, Università degli Studi di Trieste, 2018. http://hdl.handle.net/11368/2918473.

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The research has been focused on tailoring novel photosensitizers, ranging from organic molecules to carbon nanostructure, such as perylene bisimides (PBIs) and carbon nanodots (CNDs): At first it was developed a fast and efficient protocol for the microwave assisted synthesis of perylene bisimides. Imidation reactions of the perylenebisanhydride were performed using a large variety of amines, such as alkylamines, amino alcohols, heteroarylamines, and amino acids. With the powerful tool we developed, we targeted more complex applications. We designed a novel photocatalytic system mimicking the PSII oxygen evolving center. Our approach was based on the unprecedented combination of metal-free perylene bisimides (PBI) as photosensitizers with totally inorganic polyoxometalates (POMs) as catalysts. Oxygen evolution was observed with well-behaved kinetics, long operation time (> 8h), and conversion yields up to >98%. Moreover, we proposed comprehensive structural picture of a perylenebisimide hydrogel, suggesting that its long-range conductivity is limited by charge-transfer between electronic backbones. We revealed nano-crystalline ribbons as the electronic and structural backbone between which charge transfer was mediated by polar solvent bridges. We exemplified this effect with gas sensing, where exposure to polar vapor changes conductivity by five orders of magnitude, emphasizing the crucial role of the interplay between structural motif and surrounding medium for the rational design of devices based on nano-crystalline hydrogels. Jumping to carbon nanostructure we were interested into mastering optical, electronical and structural properties of carbon dots. Thus, we synthesized and characterized green emissive CNDs using organic chromophores, such as boron-dipyrromethenes, as starting materials and we exploited them as tracker in NK cells. Notably, it was optimized a synthetic protocol for the green emissive CNDs that can be extended for the preparation of a library of multicolored CNDs. Furthermore, we prepared and characterized a redox library of CNDs with tunable energy levels by adding to the reaction mixture commercially available quinones and employing a bottom-up MW-assisted hydrothermal treatment. Benzoquinone-, naphthoquinone- and anthraquinone-based carbon nanodots exhibited interesting electrochemistry with oxidation potentials between 1..48 V and 0.98 V vs SCE and reducing one in the range -1.52 V and -2.05 V vs SCE. Finally, we reported the structural and optical modifications happening during the reaction. We identified the core-shell structure of these carbon dots and synthesized novel CNDs with controlling the size of the soft shell that we believe it is the responsible for the optical properties that characterize these interesting nanoparticles.
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13

Matteucci, Elia <1988&gt. "Design and Synthesis of New Luminescent Materials: from Light Sources to Biological Applications". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7548/1/Tesi_Matteucci_Elia.pdf.

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The synthesis of luminescent metal complexes is a very challenging task since they can be regarded as the starting point for many different areas. Luminescent complexes, in fact, can be used for technological, industrial, medical and biological applications. They consist of two main parts: the central core of the complex, a metal atom, and various organic ligands bonded to it. Among all the transition metal complexes, Iridium(III) ones show the best photophysical properties: generally, they have high quantum yields, very long lifetimes and possess easily tunable emissions throughout the visible range. During my PhD I prepared different families of Ir(III) complexes suitable for various applications. In detail, my thesis deals with the synthesis of new functionalized chelating ligands that have been used to obtain phosphorescent Ir(III) complexes. In particular I synthesised isocyanides, phenyltetrazole and pyridiltriazolylidene derivatives and various corresponding Ir(III) complexes with peculiar photophysical properties, suitable for the preparation of electroluminescent devices. Moreover, I synthesized pyridiltriazole chelating ligands for the preparation of Ir(III) complexes able to be embebbed in nanoparticles. At the same time, I set up the synthesis of various carbazole-terpyridines systems containing substituent of different length and aromatic character. During my studies, I enhanced my knowledges about the techniques for the spectroscopical characterization of the obtained compounds, such as mono- and bidimensional and VT- NMR, UV-vis and spectrofluorimetry.
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14

Matteucci, Elia <1988&gt. "Design and Synthesis of New Luminescent Materials: from Light Sources to Biological Applications". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7548/.

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The synthesis of luminescent metal complexes is a very challenging task since they can be regarded as the starting point for many different areas. Luminescent complexes, in fact, can be used for technological, industrial, medical and biological applications. They consist of two main parts: the central core of the complex, a metal atom, and various organic ligands bonded to it. Among all the transition metal complexes, Iridium(III) ones show the best photophysical properties: generally, they have high quantum yields, very long lifetimes and possess easily tunable emissions throughout the visible range. During my PhD I prepared different families of Ir(III) complexes suitable for various applications. In detail, my thesis deals with the synthesis of new functionalized chelating ligands that have been used to obtain phosphorescent Ir(III) complexes. In particular I synthesised isocyanides, phenyltetrazole and pyridiltriazolylidene derivatives and various corresponding Ir(III) complexes with peculiar photophysical properties, suitable for the preparation of electroluminescent devices. Moreover, I synthesized pyridiltriazole chelating ligands for the preparation of Ir(III) complexes able to be embebbed in nanoparticles. At the same time, I set up the synthesis of various carbazole-terpyridines systems containing substituent of different length and aromatic character. During my studies, I enhanced my knowledges about the techniques for the spectroscopical characterization of the obtained compounds, such as mono- and bidimensional and VT- NMR, UV-vis and spectrofluorimetry.
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15

Delaunay, Wylliam. "Synthèse et caractérisation de nouveaux matériaux organophosphorés pour des applications en optoélectronique". Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00942602.

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Ce manuscrit décrit la synthèse et la caractérisation de nouvelles molécules incluant un cœur organophosphoré, le phosphole. Certaines de ces molécules ont été utilisées pour la fabrication de dispositifs OLEDs ou de cellules photovoltaïques organiques. Le premier chapitre fait un état de l'art de la chimie du phosphole dans le domaine des matériaux organiques entre 2010 et 2013. Le second chapitre décrit la synthèse et l'étude physico-chimique de molécules qui permettent de moduler l'angle de torsion dans les systèmes π conjugués pour faire varier les propriétés optiques et rédox. Une de ces molécules a permis la fabrication d'une diode blanche organique. Le troisième chapitre de ce manuscrit présente une structure tridimensionnelle intéressante, le 1,1-biphosphole. En plus de posséder une structure tridimensionnelle, ces structures présentent un mode de conjugaison original, la conjugaison σ-π, qui permet de réduire l'écart HO-BV de nos systèmes. Une de ces molécules a permis la fabrication de la première cellule photovoltaïque organique avec un dérivé du phosphole inséré dans la couche active. Dans une deuxième partie, ce chapitre traite également de la réactivité originale du 1,1'-biphosphole qui permet de fonctionnaliser l'atome de phosphore par une simple substitution nucléophile, permettant d'insérer une grande variété de substituants pour moduler les propriétés des molécules. Pour finir, ce manuscrit présente un quatrième chapitre qui implique le phosphole comme unité coordinante afin de réaliser des nouveaux complexes qui permettent de réaliser une ortho-métallation par activation C-H. De nouveaux complexes ortho-métallés d'Ir(III) et de Rh(III) ont été synthétisés et caractérisés.
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16

Fan, Jia. "Concentration quenching mechanism in doped OLED materials". HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/829.

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17

Levell, Jack William. "Material and device design for organic optoelectronics". Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2066.

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This thesis describes investigations into the photophysical properties of luminescent materials and their application in optoelectronic devices such as light emitting diodes and photodetectors. The materials used were all solution processable because of the interest in low cost processing of organics. I have investigated the photophysics of 1,4,5,8,9,12-hexamethyltriphenylene, a triphenylene derivative which has its luminescence enhanced by the addition of methyl groups. These groups change the planar shape of the triphenylene molecule into a twisted one, changing the symmetry of the molecule and increasing its dipole moment in absorption and emission by ~4 fold. This increased its rate of radiative deexcitation by ~20 times. In addition, the twisted shape of the molecule prevents intermolecular interactions and concentration effects from affecting the luminescence. This results in an efficient solid-state photoluminescence quantum yield of 31%. This thesis also includes an investigation into phosphorescent polymer dendrimers, designed to have suitable viscosities in solution for inkjet printed OLED applications. A photophysical study of the intra-chain aggregation effects on the luminescence was undertaken in both homopolymers and copolymers with high energy gap spacer units. Using double dendrons to increase the steric protection of the luminescent cores, the best homopolymers achieved 12.1% external quantum efficiency (39.3 cd/A) at 100 cd/m² brightness and the best co-polymer achieved 14.7% EQE (48.3 cd/A) at 100 cd/m². This compares favourably with 11.8% EQE for the best phosphorescent polymer and 16% for the best solution processed dendrimer OLED previously reported. Finally I have applied a solution processed enhancement layer to silicon photodiodes to enhance their ultraviolet response. Using a blend of materials to give favourable absorption and emission properties, 61% external quantum efficiency was achieved at 200 nm, which is better than the 20-30% typical for vacuum deposited lumogen enhancement layers used commercially.
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18

Marianetti, Giulia. "Synthesis, optical characterization and computational study of novel organic fluorophores". Doctoral thesis, Scuola Normale Superiore, 2017. http://hdl.handle.net/11384/85811.

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Over the last three decades lot of interest has been devoted to light harvesting technologies. Recent findings on global warming and energy nonrenewable resources push us to alternative means of storing energy. Sunlight stands indeed as an ideal asset to take advantage of. In this insight Luminescent Solar Concentrators (LSCs) represent a way to decrease the cost of solar photovoltaics. LSC devices usually consist in a thin slab of transparent material (glass or polymer) doped with a fluorescent dye. Upon solar irradiation, a fraction of the emitted light, through means of internal reflection, is collected at the edges of the device where photovoltaic cells are located. Compared to traditional concentrators, which make use of mirrors and lenses, these devices show numerous advantages, such as theoretical higher concentration factors, the ability to work with both diffuse and incident light and no need for tracking devices or cooling apparatuses. Organic fluorescent dyes bearing π-conjugated electron-donor and -acceptor moieties exhibit intramolecular charge-transfer (ICT) properties, and can therefore show the optical properties required by LSCs such as high quantum yield and high Stokes shift. On account of this, the present dissertation will discuss the synthesis, UV-Vis characterization and computational study of a set of novel unsymmetrical and symmetrical push-pull azole-based dyes. These compounds are characterized by a 1,3-azole 2,5 substituted with two aromatic moieties bearing electron withdrawing (EWG) or electron donating (EDG) groups. Remarkably, the introduction of an heteroaromatic ring usually improves the thermal and chemical stability and the overall polarizability of the fluorophore. The studied compounds were prepared through a robust synthetic pathway involving a palladium and copper-promoted direct C-H arylation reaction as key step. We took into account the effect of the peripheral electron poor funtionality as well as the nature of the central heteroaromatic core. In order to rationalize the experimental results we carried out TD-DFT studies, that allowed us to proper understand the charge tranfer occuring during the electronic transition. After selecting the best fluorophores for our aim, we investigated its efficiency in an LSC prototypes.
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19

Manoel, Diego da Silva [UNESP]. "Materiais híbridos de sílica/orgânico dopados com rodamina-B: propriedades luminescentes e emissão laser randômico". Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/148710.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O processo sol-gel permite a produção de materiais Híbridos Orgânicos/Inorgânicos para aplicações em óptica e fotônica. Materiais Híbridos de Sílica/orgânico unem propriedades da Sílica e dos polímeros orgânicos e permitem a incorporação de diversas moléculas orgânicas na matriz, possibilitando a obtenção de materiais fotoativos avançados. Destas moléculas destacam-se os corantes lasers, como a Rodamina-B, que possui comprimento de onda de emissão bem definido e alta eficiência quântica. Neste trabalho preparamos materiais híbridos de sílica/orgânico via processo sol-gel utilizando como precursores os alcóxidos de silício 3-glicidoxipropiltrimetoxisilano (GPTS) e tetraetilortosilicato (TEOS). Amostras ainda na fase de sol foram dopadas com Rodamina-B em concentrações variando de 0,01 a 5 mmol/L. A fluorescência das amostras foi caracterizada mostrando dependência entre as características da emissão e a concentração de dopante. Os espectros de fluorescência sofrem um deslocamento para a região do vermelho com o aumento da concentração do dopante, enquanto a intensidade de emissão apresenta maior valor para a amostra com concentração de 0,5 mmol/L. Também foram determinados os coeficientes de absorção óptica, que apresentaram comportamento linear com a concentração. A partir das amostras (sol) foram produzidos xerogéis com concentrações de Rodamina-B de 0,0386 a 19,3 mmol/L. Os espectros de fluorescência destes xerogéis também apresentaram deslocamento para a região do vermelho para maiores concentrações de dopante, a intensidade de emissão é máxima para o xerogel com concentração de 6,56 mmol/L. Os coeficientes de absorção óptica dos xerogéis apresentaram um comportamento linear com a concentração de dopante. O xerogel com concentração de 19,3 mmol/L de Rodamina-B apresentou emissão de laser randômico quando excitado com laser pulsado (532 nm, 8ns), fenômeno caracterizado por um estreitamento da banda de emissão devido a dímeros da Rodamina-B em 630 nm. Microscopia eletrônica de transmissão revelou a formação de partículas de Sílica com diâmetro médio de 6,3 nm distribuídas na matriz sólida. Estes resultados são de grande interesse para aplicações em fotônica.
Organic-Inorganic Hybrid Materials prepared by sol-gel process have applications in different areas such as optics and photonics. Silica/organic hybrid materials combine the properties from the silica and the organic polymers and can be doped with organic molecules with different optical properties, allowing preparation of advanced photoactive materials. In the wide range of photoactive organic materials one of interest is the Rhodamine-B, a laser dye which presents tunable emission and high quantum yield. In this work we have produced hybrid silica/organic samples derived from 3-glycidoxypropyltrimethoxysilane (GPTS) and tetraethylorthosilicate (TEOS) by sol-gel process. Silica/organic sols were doped with Rhodamine-B concentrations ranging from 0.01 to 5 mmol/L. The fluorescence spectra of the samples were characterized and a relationship between emission characteristics and dopant concentration has been observed. A red shift in the wavelength emission was observed, as the dopant concentration increased and the maximum emission intensity was achieved for the sample with concentration of 0.5mmol/L. Were determined the optical absorption coefficients that showed a linear relation with the concentration. The sol samples were dried and xerogels were obtained and the new concentrations of Rhodamine-B in the solid matrix were determined, ranging from 0.0386 to 19.3 mmol/L. The fluorescence spectra of the xerogels were characterized, showing a red shift as the dopant concentration increased and the maximum emission intensity was achieved for the xerogel with concentration of 6.56 mmol/L. The optical absorption coefficients of these xerogels showed a linear behavior with the dopant concentration. Random laser action for the xerogel with concentration of 19.3 mmol/L was measured using an pulsed laser (532 nm, 8ns), and characterized by a narrowing emission of the Rhodamine-B dimmers emission at 630 nm. Transmission electron microscopy revealed silica particles with 6.3 nm average diameter in the solid matrix. These results are very important for applications in photonics.
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20

Roger, Maxime. "Développement de systèmes π-conjugués aux propriétés de fluorescence induite par l'agrégation (AIE)". Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONS005.

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Le phénomène de fluorescence, bien qu’assez rare à l’état naturel, est couramment exploité dans le domaine de l’optoélectronique pour la fabrication d’OLEDs ou de concentrateurs solaires, mais aussi dans le domaine biomédical pour l’imagerie ou la thérapie. Ce travail est axé sur la conception de molécules fluorescentes présentant une émission induite par l’agrégation (AIE, « Aggregation Induced Emission »). Contrairement aux fluorophores conventionnels pour lesquels l’émission est éteinte à l’état agrégé, les fluorophores AIE possèdent un comportement inverse : ils sont peu fluorescents en solution mais le deviennent à l’état solide. Ce phénomène résulte de la restriction des mouvements intramoléculaires dans un environnement contraint (RIM, « restriction of intramolecular motion ») permettant de favoriser les voies de désexcitation radiatives. Ce manuscrit s’inscrit dans ce contexte et est divisé en quatre chapitres. Le premier décrit le concept et les conditions requises permettant à une molécule d’être dotée de la propriété AIE. Les trois suivants abordent tout d’abord la synthèse et l’étude de fluorophores AIE de la famille des diphénylebuta-1,3-diènes portant des groupements dérivés du thiophène électropolymérisables. Le chapitre suivant aborde la synthèse de systèmes donneurs-accepteurs basés sur le motif tétraphényléthène (TPE) en vue d’obtenir des propriétés d’absorption et/ou émission dans le domaine des grandes longueurs d’onde du rouge et du proche infrarouge (600 nm-1200 nm). Enfin, le dernier chapitre, s’intéresse au contrôle et à la modulation de la longueur d’onde d’émission en exploitant le comportement AIE de deux fluorophore à base de TPE et de quinoline malononitrile induit par la transition de phase soluble/insoluble d’un polymère thermosensible, la poly(2-n-propyl-2-oxazoline).Mot clés : Design moléculaire, fluorophore, fluorescence, émission induite par l’agrégation, AIE, synthèse organique, diphénylbuta-1,3-diène, tétraphényléthène, quinoline malononitrile, poly(2- oxazoline)
The fluorescence phenomenon while relatively rare in nature, is also commonly operating in various fields including optoelectronics for the conception of OLEDs and solar concentrators and biomedicals for imaging and therapy. This work falls into this context and aims at designing fluorescent molecules possessing aggregation induced emission (AIE) properites. In contrast to conventional fluorophores that suffer of aggregation caused quenching (ACQ) phenomenom, AIE fluorophores exhibit in general strong emission in the solid state while there are non-emissive in solution due to the restriction of intramolecular motion (RIM) which favor the radiative decay. This manuscript is built upon four chapters. The introduction describes the concept and the conditions required for a molecule to exhibit a AIE behaviour. The second chapter describes the synthesis and the characterization of AIEbased diphenylbuta-1,3-diene skeleton bearing electropolymerizable thiophene moieties. The third chapter is related to the development of donor-acceptor systems built upon a tetraphenylethene (TPE) core in view of extending their absorption / emission properties to the red or near infrared (600 nm - 1200 nm) region of the spectrum. Finally, the last chapter deals with the control and the modulation of the emission wavelength by exploiting the AIE behavior of two fluorophores based on tetraphenylethene and quinoline malononitrile induced by the folding of the chain of a thermoresponsive polymer, the poly(2-n-propyl-2-oxazoline).Keywords: Molecular design, fluorophore, fluorescent, aggregation induced emission, AIE, organic synthesis, diphénylbuta-1,3-diène, tetraphenylethene, quinoline malononitrile, poly(2-oxazoline)
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21

Tessarolo, J. "Design and synthesis of metallo-supramolecular architectures towards advanced materials". Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422402.

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Self-assembly is a key step to obtain functional supramolecular objects towards complex matter. With self-assembly of metal ions and well-designed polytopic ligands is possible to access a particular class of supramolecular functional materials: metal-organic polygons and polyhedra endowed with confined space, and functional properties deriving from the building blocks. Herein, firstly is presented a system that in solution self-assembles in a collection of Cu(II) based boxes: a rhomboid and a triangle in dynamic equilibrium. This system is a small constitutional dynamic library (CDL). The designed introduction of well-suited guests allows to orchestrate the system response and select the triangular box by host-guest interactions. This system is an excellent bench test to explore the possibility to modulate the reactivity of guest molecules. Two examples of reactivity in the environment of the triangular host are here reported: the oxidation of a guest molecule under soft conditions and an extremely selective C-N bonds cleavage of another guest molecule. The nature of this multifaceted system has been unraveled by a combination of FT-IR spectroscopy, absorption spectroscopy and single crystal structural studies. Afterward, the synthesis of two new ligands libraries, a series of bis-β-diketone ligands and a series of tris-β-diketone ligands, specifically designed for the self-assembly of metallo-supramolecular cages, has been developed. The two libraries have been combined with both transition metal and lanthanoid ions in order to self-assemble metal-organic polyhedra. By reaction of the tris-β-diketone with Fe3+ ions, the rational design of and the self-assembly of a series of Fe4L4 supramolecular tetrahedra with space confined cavities able to host guest molecules, has been achieved. The formation of the capsules is confirmed by single crystal X-ray diffraction studies. The bis-β-diketone ligands have been reacted with Eu3+ ions leading to the self-assembly of a series of charged [Eu2L4]2-¬ and neutral [Eu2L3] dimeric capsules. In this systems, the structural features of metallo-supramolecular cages are combined with the peculiar optical properties of lanthanoid ions, leading to the self-assembly of luminescent coordination-driven capsules. The capsules have been studied through ESI-MS and 1H-NMR analyses. Luminescence and quantum yields have been characterized.
L’auto-assemblaggio, ovvero l’organizzazione spontanea e reversibile di componenti preesistenti in strutture supramolecolari, è un processo che può essere utilizzato per la preparazione di sistemi con proprietà funzionali, tramite. Nello specifico, tramite auto-assemblaggio di ioni metallici e leganti politopici è possibile generare una particolare classe di materiali funzionali supramolecolari: poligoni e poliedri metallo-organici dotati di tasche e spazi confinati di dimensione molecolare. In questo lavoro viene dapprima presentato un sistema basato su Cu(II) e un legante bis-β-dichetonato. In soluzione i componenti si auto-assemblano in una serie di box supramolecolari: un dimero ed un trimero in equilibrio dinamico tra loro. Questo sistema è una piccola libreria costituzionale dinamica (CDL). L’equilibrio tra i due costituenti della CDL può essere orchestrato tramite l’introduzione di piccole molecole che, venendo accomodate nella tasca molecolare della specie trimerica, riescono a selezionarla tramite interazioni di tipo host-guest. Questo sistema si è un eccellente modello per studiare la reattività di piccole molecole ospitate in spazi confinati. In questo lavoro sono presentati due esempi di reattività di piccole molecole ospitate nella tasca triangolare: un ossidazione in condizioni blande e la rottura selettiva di un legame C-N. Queste reazioni sono state studiate con una combinazione di spettroscopia FT-IR, UV-Vis e diffrazione a raggi X su cristallo singolo In seguito, è stata sviluppata la sintesi di due nuove librerie di leganti, una serie di leganti bis-β-dichetoni e una serie di leganti tris-β-dichetoni, progettati specificatamente per poter formare capsule metallo-supramolecolari. La reazione di questi leganti con metalli di transizione e con ioni lantanoidi porta alla formazione di poliedri metallo-organici. Nello specifico, l’auto-assemblaggio dei leganti tris-β-dichetoni con lo ione Fe3+ porta alla formazione di tetraedri supramolecolari, di formula generale Fe4L4. Tali capsule sono caratterizzate dalla presenza di tasche di dimensioni sufficienti a contenere piccole molecole. La struttura delle capsule tetraedriche è stata confermata tramite diffrazione a raggi X su cristallo singolo. L’auto-assemblaggio dei leganti bis-β-dichetoni con lo ione Eu3+ porta alla formazione di una serie di capsule dimeriche che possono essere cariche negativamente ([Eu2L4]2-¬) oppure neutre ([Eu2L3]). Questo sistema presenta proprietà funzionali: la luminescenza dello ione lantanoide è attivata tramite effetto antenna indotto dal legante. La formazione di queste capsule metallo-supramolecolari luminescenti è stata studiata tramite spettrometria ESI-MS e spettroscopia 1H-NMR. Infine sono state caratterizzate le proprietà di fotoluminescenza (emissione e rese quantiche) dei sistemi [Eu2L4]2-¬.
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22

Kammoe, Astride Lorette. "Synthesis and Characterization of Multifunctional Organic/ inorganic Hybrid Materials obtained by the "wet chemistry" approach". Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-175649.

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Die vorliegende Arbeit fokussiert auf die Synthese von organisch/anorganischen Hybridmaterialien mit multifunktionalen Eigenschaften unter ausschliesslicher Darstellung dieser Materialen mit Hilfe des „wet chemistry“ Zugangs. Ausgehend von der Darstellung und Charakterisierung von isomorphen bzw. isostrukturellen Hybridmaterialien der allgemeinen Zusammensetzung catena-{[Me3NH][MCl3·2H2O]}n (Mtac) (MII = Mn, Co, Ni, Cu, tac = [Me3NH]Cl3·2H2O]) speziell mittels IR und UV/vis Spektroskopie ist beschrieben, wie sich aus diesen entsprechende bi-, tri-, und auch tetra-heterometallische Koordinationspolymere der allgemeinen Zusammenseztung {MxM´ytac}n, {MxM´yM´´ztac}n, {MxM´yM´´zM´´´ttac}n (MII = M ≠ M´≠ M´´≠ M´´´≠ M´´´´ und x, y, z, t als prozentualer Metallgehalt) herstellen lassen und welche limitierende Faktoren zu berücksichtigen sind. Leifähigkeitsmessungen an Einkristallen ausgewählter Koordinationspolymere werden vorgestellt. Zusätzlich werden die durch Rekristallisation von Nitac erhaltenen zwei verschiedenen Koordinationspolymere der Formel {[Me3NH]3{NiCl4}{NiCl3}}n und {[(Me3NH]{NiCl3}}n in Bezug auf ihre ungewöhnlichen strukturellen und magnetischen Eigenschaften vorgestellt und beschrieben. Die durch Austausch von [Me3NH]+ Kationen gegen [Et3NH]+ bzw. protonierten aromatischen N-haltigen Kationen wie [2,2’-bipyH2]2+, [4,4’-bipyH2]2+ and [1,10-phenH2]2+ erhaltenen Reaktionsprodukte aus Umsetzungen mit Hilfe des “wet chemistry” Zugangs werden im Hinblick auf ihre Festkörperstrukturen beschrieben. Die erfolgreiche Darstellung einer neuen Familie von perylentetracarboxylato-basierenden Komplexen, die teilweise hervorragende Löslichkeiten besitzen, wird beschrieben sowie die strukturellen, magnetischen und lumineszierenden Eigenschaften ausgewählter Vetreter
The thesis presented here is focused on the synthesis of organic/ inorganic hybrid materials with multifunctional properties by means of the “wet chemistry” approach. The synthesis and characterization of hybrid materials with the general composition catena-{[Me3NH][MCl3·2H2O]}n (Mtac) (MII = Mn, Co, Ni, Cu, tac = [Me3NH]Cl3·2H2O]) is described. Due to their isomorphic and/ or isostructural character, bi-, tri-, and even tetra-heterometallic chains of the general formula {MxM´ytac}n, {MxM´yM´´ztac}n, {MxM´yM´´zM´´´ttac}n (MII = M ≠ M´≠ M´´≠ M´´´≠ M´´´´ and x, y, z, t is the percentage of each metal content) were synthesized and characterized. Limitating factors of the synthesis of these types of heterometallic coordination polymers are discussed. Furthermore, the conductive properties of selected representatives were investigated. Additionally, the products obtained from recrystallization of Nitac, two different novel 1D coordination polymers of the formula {[Me3NH]3{NiCl4}{NiCl3}}n and {[(Me3NH]{NiCl3}}n are described with respect to their structural and magnetic properties. Efforts to replace the [Me3NH]+ cations of Mtac compounds by [Et3NH]+ cations as well as by protonated aromatic amines as [2,2’-bipyH2]2+, [4,4’-bipyH2]2+ and [1,10-phenH2]2+ are reported next with respect to the structural exploration of obtained hybrid materials by the “wet chemistry” approach. Finally, the synthesis of a new family of perylene tetracarboxylate (ptc) based soluble complexes is reported. Structural, magnetic and luminescence properties of selected representatives of this new series of soluble ptc derivatives are reported
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23

Cai, Muzhi. "Hybrid materials based on inorganic glasses doped with organophosphorus molecules for light emitting electrochemical cell applications". Thesis, Rennes, INSA, 2019. http://partages.insa-rennes.fr/share/page/document-details?nodeRef=workspace://SpacesStore/cc6fb318-d6f8-4126-8db4-a2a825a605a7.

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La cellule électrochimique électroluminescente (LEC) est un dispositif à couches minces, composé d’un semi-conducteur organique électroluminescent (OSC) et d’ions mobiles en tant que matériau actif intercalé entre une anode et une cathode. Dans le premier chapitre, le contexte et le mécanisme de la LEC ont été introduits. Dans le deuxième chapitre, nous avons dopé la molécule organophosphorée dans un verre de silicate contenant une teneur élevée en lithium par la méthode sol-gel. Dans le troisième chapitre, nous avons travaillé à l’obtention d’un verre de phosphate dopé à une molécule organophosphorée avec une conductivité ionique élevée par frittage Spark Plasma Sintering (SPS). Un verre de phosphate hybride ayant une conductivité ionique d'environ 10 -7 S / cm a été obtenu et une forte photoluminescence a été observée. En outre, les propriétés électrochimiques ont également été étudiées. De plus, lors du processus de préparation de la LEC par SPS, un phénomène intéressant a été découvert. Une émission bleue à large bande a été observée dans le verre d’oxynitrure de phosphate de zinc exempt de terres rares. Le quatrième chapitre est consacré à ce phénomène
The light-emitting electrochemical cell (LEC) is a planar layered device, which is comprised of an electroluminescent organic semiconductor (OSC) and mobile ions as the active material sandwiched between an anode and a cathode. Electrolyte is one of the “short slab” of LEC technology. The main objective of this work is developing a new LEC device based on organophosphorus molecule doped organic-inorganic hybrid glass electrolyte. This hybrid glass cannot be synthesized by using classic melt-quenching technique because the melting temperature of glass is always much higher than the degradation temperature of organic molecule. Thus, in this work, we devote to that how to dope the organophosphorus molecule into the glass with high ionic conductivity. In first chapter, the background and mechanism of LEC were introduced. In the second chapter, we attempted to dope the organophosphorus molecule into silicate glass containing high lithium content by sol-gel method. In third chapter, we are working to obtain organophosphorus molecule doped phosphate glass with high ionic conductivity through spark plasm sintering (SPS). A hybrid phosphate glass with ionic conductivity of around 10 -7 S/cm was obtained, and strong photoluminescence was observed. Besides, the electrochemical properties were investigated as well. Moreover, during the process of preparing the LEC by SPS, an interesting phenomenon was found. A broadband blue emission was observed in rare-earth free zinc phosphate oxynitride glass. The fourth chapter is focus on this interesting phenomenon
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24

Alpha, Béatrice. "Cryptates photoactifs de lanthanides : de nouveaux marqueurs luminescents". Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13204.

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Synthese de nouveaux cryptanols et de leurs complexes de lanthanides. L'inclusion de ces metaux permet d'augmenter considerablement l'intensite d'emission de l'ion, constituant ainsi une nouvelle classe de marqueurs luminescents
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25

Robin, Malo. "Développement de transistors à effet de champ organiques et de matériaux luminescents à base de nanoclusters par impression à jet d’encre". Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S105/document.

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L'objectif de cette thèse était de démontrer les potentialités de l'impression à jet d'encre pour le pilotage d'une HLED contenant des clusters métalliques phosphorescents dans le rouges, par des transistors organiques à effet de champs. Pour atteindre ce but, le projet a été divisé en deux parties : I) La fabrication et l'optimisation de transistors organiques de type n par photolithographie puis le transfert technologique vers l'impression à jet d'encre. II) Parallèlement au développement des transistors, je me suis attaché à la conception de matériaux hybrides luminescents pour la réalisation d'HLED. Pour la partie transistor, nous avons obtenu une meilleure compréhension des facteurs influençant l'injection de charges mais aussi la stabilité électrique pour un transistor de géométrie grille basse/contacts bas avec le fullerène C60 évaporé. Nous avons démontré que la résistance de contact est d'une part gouvernée par la morphologie du SCO au niveau des électrodes et d'autre part indépendante du travail de sortie du métal. En outre, nous avons vu que la stabilité électrique des transistors est fortement impactée par la nature du contact source et drain. L'optimisation des transistors fabriqués par photolithographie, qui a essentiellement consisté à modifier les interfaces, nous a permis de développer des transistors de type n performants avec des mobilités à effet de champ saturées allant jusqu'à 1,5 cm2/V.s pour une température maximum de procédé de 115 °C. Le transfert vers un transistor fabriqué par impression à jet d'encre a ensuite été effectué. Nous avons ensuite démontré que les morphologies de l'électrode de grille et de l'isolant, fabriqués par impression à jet d'encre, ont un impact négligeable sur les performances des transistors. Pour notre structure imprimée, l'injection de charges aux électrodes S/D est en fait le facteur clé pour la réalisation de transistors performants. Finalement, des matériaux phosphorescents rouges à base de cluster métalliques octaédrique de molybdène ont été développés. Le copolymère hybride résultant présentait un rendement quantique de photoluminescence de 51 %. La réalisation de l'HLED a ensuite été effectuée par combinaison d'une LED bleue commercial et du copolymère dopé avec des clusters octaédriques de molybdène pour des applications possibles en biologie ou dans l'éclairage
The objective of this thesis was to demonstrate the potentialities of inkjet printing for driving an HLED containing red phosphorescent metallic clusters, with organic field effect transistors. To achieve this goal, the project was divided into two parts: I) The fabrication and optimization of n-type organic transistors by photolithography and then transfer to inkjet printing. II) Parallel to the development of transistors, I focused on designing luminescent hybrid materials for HLED realization. Concerning transistors, we obtained a better understanding of the factors influencing the charge injection but also the electrical stability for bottom gate/ bottom contact geometry transistor with evaporated C60 semiconductor. We have demonstrated that the contact resistance is on the one hand governed by the morphology of the SCO at the electrodes and on the other hand independent of the metal work function. In addition, we have observed that transistors electrical stability of is strongly impacted by the source and drain contact nature. The optimization of photolithography transistors, which essentially consisted of modifying the interfaces, allowed us to develop efficient n-type transistors with saturated field effect mobilities of up to 1.5 cm2/V.s for a maximal process temperature of 115 °C. The technological transfer to inkjet printed transistors was then performed. We then demonstrated that gate electrode and insulator morphologies deposited by inkjet printing, have a negligible impact on transistors performances. For our printed structure, charges injection at the S/D electrodes is in fact the key factor for high performance transistors realization. Finally, red phosphorescent materials based on molybdenum octahedral metal cluster have been developed. The resulting hybrid copolymer showed photoluminescence quantum yield up to 51%. The realization of the HLED was then carried out by combining a commercial blue LED and the copolymer doped with octahedral molybdenum clusters for possible applications in biology or lighting
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26

Ashoka, Sahadevan Suchithra. "Anilate-based molecular building blocks for metal-organic frameworks and molecular conductors Conducting Anilate-Based Mixed-Valence Fe(II)Fe(III) Coordination Polymer: Small-Polaron Hopping Model for Oxalate-Type Fe(II)Fe(III) 2D Networks Nanosheets of Two-Dimensional Neutral Coordination Polymers Based on Near-Infrared-Emitting Lanthanides and a Chlorocyananilate Ligand". Thesis, Angers, 2019. http://bu.univ-angers.fr/Contact.

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Ce travail porte sur la synthèse et la caractérisation de matériaux moléculaires fonctionnels basés sur la molécule anilate et présentant des propriétés de conductivité, de magnétisme et de luminescence. Les anilates sont des dérivés de la 2,5-dihydroxy-1,4-benzoquinone substitués en positions 3 et 6 par une variété d’éléments (H, F, Cl, Br, I, CN, etc). Parmi eux, le seul composé hétérosubstitué ClCNAn2- a été choisi pour préparer une nouvelle famille de polymères de coordination bidimensionnels (PC 2D) avec des métaux de transition ou des ions lanthanides : i) un PC à valence mixte FeIIFeIII, de formule [TAG][FeIIFeIII(ClCNAn)3], contient pour la première fois le cation triaminoguanidinium dans un réseau de coordination.ii) Des PC basés sur le ligand ClCNAn2- et des ions lanthanides émettant dans le proche infrarouge (YbIII, NdIII, ErIII). Ces composés ont été exfoliés en monocouches, et des études de photoluminescence ont été menées à la fois sur les cristaux et les monocouches. iii) Une famille de PC hétéroleptiques basés sur des ions lanthanides et sur deux types de ligands pontants, le ligand ClCNAn2- et des ligands de type carboxylates (DOBDC et F4-BDC). iv) Une famille de PC basés sur des ions DyIII ont été préparés afin d’étudier leur propriétés magnétiques. v) Finalement, la capacité des ligands anilates à se combiner à des conducteurs moléculaires basés sur le BEDT-TTF a été démontrée à travers la synthèse et l’électrocristallisation de semiconducteurs organiques et de conducteurs magnétiques hybrides avec l’anion [Fe(ClCNAn)3]3-
This work reports on the design, synthesis and characterization of novel anilate-based functional molecular materials showing luminescent, magnetic and/or conducting properties. The family of anilate ligands comprises several derivatives obtained by introducing various substituents (H, F, Cl, Br, I, CN, etc.) at the 3 and 6 positions of the common 2,5-dihydroxy-1,4-benzoquinone framework. Among the anilate ligands, the only known heterosubstituted anilate with Cl/CN substituents at the 3,6 positions, ClCNAn2-, have been selected for preparing a novel family of 2D layered coordination polymers (2D CP) with both 3d metal ions and 4f lanthanide ions, through a general and straightforward synthetic strategy. i) Mixed-valence FeIIFeIII 2D CP, formulated as [TAG][FeIIFeIII(ClCNAn)3], containing, the tris(amino)-guanidinium (TAG) cation for the first time in such 2D networks has been synthesized and thoroughly characterized. ii) 2D CPs based on NIR-emitting lanthanides (YbIII, NdIII, ErIII) and the ClCNAn2- ligand, have been prepared and characterized. These layered compounds were exfoliated to nanosheets, by sonication-assisted solution synthesis. Time-resolved photoluminescence studies performed on both the bulk and nanosheets are also highlighted. iii) Novel family of heteroleptic 2D CPs based on NIR-emitting lanthanides and mixed ligands (ClCNAn2- and carboxylate ligands (DOBDC and F4-BDC)), were prepared and characterized. vi) Novel family of 2D CPs based on DyIII and ClCNAn2- were prepared in order to investigate their magnetic properties. v) Furthermore, the ability of anilate ligands to work as components of BEDT-TTF- based molecular conductors have been demonstrated through the synthesis, via electrocrystallization technique. vi) П-d hybrid multifunctional paramagnetic molecular conductors BEDT-TTF and [Fe(ClCNAn)3]3-) were also studied
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27

Lindh, E. Mattias. "Bilayer Light-Emitting Electrochemical Cells for Signage and Lighting Applications". Licentiate thesis, Umeå universitet, Institutionen för fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-114500.

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Artificial light surrounds us in a manifold of shapes. It is mainly utilized for illumination, but also for graphical communication of complex and evolving messages and information, among other things. It can be generated in different ways with incandescent lamps and fluorescent tubes constituting two common examples. Organic solid state light-generation technologies, which boast advantages such as solution processability, thin and flexible form factors, and large versatility, are modern additions to the field. But regardless of the means of generation, whenever light is to be used to communicate information, as signage or displays, it needs to be patterned. Unfortunately patterning is often complicated and expensive from a fabrication point of view, or renders the devices inefficient. To bridge the gap between present technologies and the need for low-cost and low-complexity patterned light emitters, it is important to develop new device architectures and/or fabrication procedures. In this thesis we show that patterned light emission can be attained from solution processable bilayer light-emitting electrochemical cells (LECs), in which the bilayer stack comprises an electrolyte and an organic semiconductor as the first and second layer, respectively. We investigate a subtractive direct-write approach, in which electrolyte is displaced and patterned by the contact motion of a thin stylus, as well as an additive inkjet-patterning technique. Both result in electroluminescent patterns, e.g., light-emitting sketches and microscopic signage with high pixel density. But they can also build macroscopic patterned regions with homogeneous emission depending on the design of electrolyte features. Using an in-operando optical microscopy study we have investigated the operational physics and some limiting factors of the bilayer LECs. More specifically we find that the electrolyte film homogeneity is a key property for high optical quality, and that the emitting region is defined by the location of the interfaces between electrolyte, anode, and organic semiconductor. We observe that the cationic diffusion length is less than one micrometer in our employed organic semiconductors, and rationalize the localized emission by cationic electric double-layer formation at the cathode, and the electronically insulating electrolyte at the anode. To date, the presented luminescent signage devices feature high-resolution patterns, in both pixelated and line-art form, and show great robustness in terms of fabrication and material compatibility. Being LECs, they have the potential for truly low-cost solution processing, which opens up for new applications and implementations. However, these first reports on patterned bilayer LECs leave plenty of room for improvements of the optical and electronic characteristics. For instance, if the optoelectronic properties of the devices were better understood, a rational design of microscopic electrolyte features could provide for both more efficient LECs, and for more homogeneous light emission from the patterned regions.
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28

Felouat, Abdellah. "Synthèse et études photophysiques de matériaux PI-conjugés - Complexes de difluorure de Bore des ligands Beta-dicétone à conjugaison PI-étendue". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4036.

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Une nouvelle famille de complexes de difluorure de bore photosensibles est développée. Elle est basée sur des structures moléculaires contenant une unité β-dicétone à conjugaison électronique π.La grande variété de groupements aromatiques et la nature donneur ou accepteur d'électrons des différents substituants permet l'élaboration de systèmes électroniques donneur-accepteur-donneur d'électrons (D1-A-D1) et donneur-accepteur (D2-A).L'absorption électronique de cette famille de molécule se situe dans la partie visible du spectre électromagnétique et une partie du spectre ultraviolet, et est caractérisée par une bande d'absorption π-π* intense avec des coefficients d'absorption molaire supérieurs à 50 000 M-1cm-1.L'émission de fluorescence couvre une plage spectrale qui va du visible au proche infrarouge avec des rendements quantiques de fluorescence en solution relativement élevés pouvant atteindre 62 %.En fin, cette famille de molécule est photochimiquement stable et est, contrairement à d'autres familles de complexes de difluorure de bore, chimiquement très stable en solution.Mots-clés : Difluorure de bore, β-dicétone, matériaux π-conjugués, luminescence, fluorescence stationnaire et résolue dans le temps (TRES), synthèse organique, RMN-19F dynamique, complexes & colorants fluorescents, curcumine & curcuminoide, complexe BF2, photophysique
A new photosensitive family of boron difluoride complex is developed. It is based on π-conjugated molecular structures containing β-diketonates unit.The wide variety of aromatic groups and the nature of donor or electron acceptor of the different substituents allow the development of electron donor-acceptor-donor (DAD) and donor-acceptor (DA) electronic systems.The electronic absorption of this family of molecules is in the visible part of the electromagnetic spectrum and a portion of the ultraviolet spectrum, and is characterized by an intense π-π* absorption band with molar absorption coefficient greater than 50 000 M-1.cm-1.The fluorescence emission covers a spectral range going from visible to near infrared, with relatively high fluorescence quantum yields of up to 62 % in solution.This new material family is photochemically stable and, unlike some other families of boron difluoride complexes, chemically very stable in solution
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29

"Metal Ion Detection by Luminescent Metal Organic Frameworks". Master's thesis, 2018. http://hdl.handle.net/2286/R.I.49033.

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abstract: Metal Organic Frameworks(MOFs) have been used in various applications, including sensors. The unique crystalline structure of MOFs in addition to controllability of their pore size and their intake selectivity makes them a promising method of detection. Detection of metal ions in water using a binary mixture of luminescent MOFs has been reported. 3 MOFs(ZrPDA, UiO-66 and UiO-66-NH2) as detectors and 4 metal ions(Pb2+, Ni2+, Ba2+ and Cu2+) as the target species were chosen based on cost, water stability, application and end goals. It is possible to detect metal ions such as Pb2+ at concentrations at low as 0.005 molar using MOFs. Also, based on the luminescence responses, a method of distinguishing between similar metal ions has been proposed. It is shown that using a mixture of MOFs with dierent reaction to metal ions can lead to unique and specic 3D luminescence maps, which can be used to identify the present metal ions in water and their amount. In addition to the response of a single MOF to addition of a single metal ion, luminescence response of ZrPDA + UiO-66 mixture to increasing concentration of each of 4 metal ions was studied, and summarized. A new peak is observed in the mixture, that did not exist before, and it is proposed that this peak requires metal ions to activate
Dissertation/Thesis
Masters Thesis Materials Science and Engineering 2018
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30

GUO, TING-WEI, i 郭庭維. "Preparation and study of luminescent materials for organic light emitting diodes". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/xsrjhn.

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碩士
明志科技大學
材料工程系碩士班
106
In this study, the organic halogenated perovskite MAPbX3 (MA = CH3NH3, X = Cl, Br, I) materials were prepared and applied in the organic light-emitting diode (OLED) as a fluorescent layer. The energy level of photon for the halogenated perovskite materials could be tuned to reach a wide color gamut and high purity of RGB colors. In the preparation, many important operating conditions, including the different ratios of solvents (DMF:CB), addition of polymer additives (P2VP, PI), and the effect of modified layer (COC, PMMA), were optimized to enhance the fluorescence intensity for the perovskite materials. In the analysis of optical properties, the photoluminescence was used for the fluorescent solutions (Quantum Dots) and hybrid films. Moreover, the perovskite materials with the best film deposition properties, high crystallinity, and good fluorescence intensity were selected to apply in the OLED device as a fluorescent layer. The results of this study showed that the OLED device made of an organic halogenated perovskite fluorescent material as a light-emitting layer could be prepared by the method shown in this study, and a voltage of 5 V could successfully light the device and show the green fluorescence. The best fluorescence intensity, fluorescent purity, and device stability were 1.54*108 PL Counts, FWHM=26-28 nm, and 1 h, respectively.
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31

Mukherjee, Sanjoy. "Investigations of Structure-Property Relationships in NPI and BODIPY Based Luminescent Material". Thesis, 2015. http://etd.iisc.ac.in/handle/2005/3933.

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Luminescent materials find numerous applications in recent times and have enriched human lives in several different ways. From display and lighting technologies to security, sensing and biological investigations, luminescent organic compounds have become indispensible and often preferred over their inorganic counterparts. The versatility of organic materials arises from their comparative low costs, ease of fine-tuning, low toxicity and the possibility to develop flexible devices. Even until very recent times, the investigations and usage of organic luminescent materials were mostly limited to solution-state properties. However, with progress of available characterisation techniques and parallel development of their usage in solid-state devices and other applications (e.g. security, forensics, sensing etc.), significantly greater attention has been paid to the development and investigations of solid-state emissive organic materials. In solid-state applications, apart from the molecular properties of any given material, their cumulative i.e. bulk physical properties are of even greater importance. Thus, investigations of structure-property relationships in organic luminescent compounds to understand their molecular and bulk properties are of fundamental interest. In this thesis, NPI (1,8-naphthalimide) and BODIPY (boron-dipyrromethene) dyes were investigated to provide a broad overview of their structure-property correlations. Among commonly encountered organic luminescent materials, NPIs and BODIPYs have emerged as two broad classes of luminescent organic compounds, finding applications as functional luminescent materials in various fields. However, lack of understanding for controlling the cumulative emissive properties of these compounds has limited their usage as active solid-state emitters in various applications. This thesis presents several new insights into the molecular and bulk emissive properties of these two classes of luminescent dyes (NPIs and BODIPYs). The contents of the six chapters contained in this thesis are summarised below. Chapter 1 summarises the available understanding of the basic concepts of photoluminescence and the design strategies to develop solid-state luminescent and AIE (aggregation-induced emission) active materials. This chapter also emphasises in the basic nature of the NPI and BODIPY compounds, their substitution patterns and their inherent characteristics and touches upon the relatively unexplored properties of NPI and BODIPY based materials. The importance and scope of the work reported in the thesis is outlined at the end of the chapter. Chapter 2 describes a detailed investigation of a series of seven (4-oxoaryl substituted) NPI compounds (1-7) providing an insight into the molecular and cumulative photophysical behaviour of these compounds. The low ICT characteristics of the NPIs, coupled with the twisted geometry, facilitated solid-state luminescence in these materials. The solution and solid-state luminescent properties of these compounds can be directly correlated to their structural rigidity, nature of substituents and solid-state intermolecular interactions (e.g. π-π stacking, C-H•••O interactions etc.). The solid-state crystal structures of the NPI siblings are profoundly affected by the pendant substituents. All of the NPIs (1-7) show antiparallel dimeric π-π stacking interactions in the solid-state which can further extend in parallel, alternate, orthogonal or lateral fashion depending on the steric and electronic nature of the C-4′ substituents. Structural investigations including Hirsfeld surface analysis methods reveal that while strongly interacting systems show weak to moderate emission in their condensed states, weakly interacting systems show strong emission yields under the same conditions. The nature of packing and extended structures also affects the emission colors of the NPIs in the solid-state. DFT computational studies were utilized to understand the molecular and cumulative electronic behavior of the NPIs. Apart from the investigation of solid-state luminescence, other functional potentials of these NPIs were also explored. One of the compounds (i.e. 4) shows chemodosimetric response towards aqueous Hg(II) species with a ‘turn-on’ response. Also, depending on the molecular flexibility of the compounds, promising AIEE (aggregation-induced emission enhancement) features were observed in these NPIs. Later (in Chapter 3), we developed a systematic investigation in a series of purely organic NPIs, restricting various parameters, to attain a thorough understanding of such AIEE properties. Chapter 3 describes a detailed experimental and computational study in order gain an insight into the AIE (aggregation-induced emission) and AIEE mechanisms in NPI compounds. Systematic structural perturbation was used to fine tune the luminescence properties of three new 1,8-naphthalimides (8-10) in solution and as aggregates. The NPIs (8-10) show blue emission in solution state and the fluorescence quantum yields depend on their molecular rigidity. In concentrated solutions of the NPIs, intermolecular interactions were found to result in quenching of fluorescence. In contrast, upon aggregation (in THF:H2O mixtures), two of the NPIs show aggregation-induced-emission-enhancement (AIEE). The NPIs also show moderately high solid-state emission quantum yields (~10-12.7 %). The AIEE behaviors of the NPIs depend on their molecular rigidity and nature of intermolecular interactions. The NPIs (8-10) show different extents of intermolecular (π-π and C-H•••O) interactions in their solid-state structures depending on their substituents. Detailed photophysical, computational and structural investigations suggest that only an optimal balance of structural flexibility and intermolecular communication is the effective recipe for achieving AIEE characteristics in these NPIs. Chapter 4 presents the design, synthesis and detailed investigations and potential applications of a series of NPI-BODIPY dyads (11-13). The NPI and BODIPY moieties in these dyads are electronically separated by oxoaryl bridges and the compounds only differ structurally with respect to methyl substitutions on the BODIPY fluorophore. The NPI and BODIPY moieties retain their optical features in these molecular dyads (11- 13). Dyads 11-13 show dual emission in solution state originating from the two separate fluorescent units. The variations of the dual emission in these compounds are controlled by the structural flexibility of the systems. The dyads also show significant AIES (Aggregation-Induced-Emission Switching) features upon formation of nano-aggregates in THF-H2O mixtures with visual changes in emission from green to red color. Whereas the flexible and aggregation prone system (i.e. compound 11) shows aggregation-induced enhancement of emission, rigid systems with less favorable intermolecular interactions (i.e. compound 12-13) show aggregation-induced quenching of emission. The emission-intensity vs. the structural-flexibility correlations were found to be reverse in solution and aggregated states. Photophysical and structural investigations suggest that the intermolecular interactions (e.g. π-π stacking etc.) play major role in controlling emission of these compounds in aggregated states. Similar trends were also observed in the solid-state luminescence of these compounds. The applications of the luminescent dyads 11-13 as live-cell imaging dyes was also investigated. Chapter 5 describes investigations of photophysical properties of a series of six BODIPY dyes (14-19) in which there is a systematic alteration of a common -C6H4Si(CH3)3 substituent. Inrelated constitutional isomers, the systematic increment of steric congestion and lowering of molecular symmetry around the BODIPY core result in a steady increment of solution and solid- state fluorescence quantum yields. The increasing fluorescence quantum yields (solution, solid state) with increasing steric congestions show that the molecular free rotation and aggregation-induced fluorescence quenching of BODIPYs can be successfully suppressed by lowering the flexibility of the molecules. Photophysical and DFT investigations reveal that the electronic band gap in any set of these constitutional isomers remain almost similar. However, the crystal structures of the compounds reveal that the solid-state colour and quantum yields of the compounds in solid-state are also related to the nature of intermolecular interactions. Chapter 6 demonstrates the use of DFT computational methods to understand the effect of alkyl groups in governing the basic structural and electronic aspects of BODIPY dyes. As demonstrated in Chapter 4 and Chapter 5, apparently electronically inactive alkyl groups can be of immense importance to control the overall photophysics of BODIPYs. In this context, a systematic strategy su was utilized considering all possible outcomes of constitutionally-isomeric molecules to understand the effects of alkyl groups on the BODIPY molecules. Four different computational methods were employed to ascertain the unanimity of the observed trends associated with the molecular properties. In line with experimental observations, it was found that alkyl substituents in BODIPY dyes situated at 3/5-positions effectively participate in stabilization as well as planarization of such molecules. Screening of all the possible isomeric molecular systems was used to understand the individual properties and overall effects of the typical alkyl substituents in controlling several basic properties of such BODIPY molecules.
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32

Mukherjee, Sanjoy. "Investigations of Structure-Property Relationships in NPI and BODIPY Based Luminescent Material". Thesis, 2015. http://etd.iisc.ernet.in/2005/3933.

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Luminescent materials find numerous applications in recent times and have enriched human lives in several different ways. From display and lighting technologies to security, sensing and biological investigations, luminescent organic compounds have become indispensible and often preferred over their inorganic counterparts. The versatility of organic materials arises from their comparative low costs, ease of fine-tuning, low toxicity and the possibility to develop flexible devices. Even until very recent times, the investigations and usage of organic luminescent materials were mostly limited to solution-state properties. However, with progress of available characterisation techniques and parallel development of their usage in solid-state devices and other applications (e.g. security, forensics, sensing etc.), significantly greater attention has been paid to the development and investigations of solid-state emissive organic materials. In solid-state applications, apart from the molecular properties of any given material, their cumulative i.e. bulk physical properties are of even greater importance. Thus, investigations of structure-property relationships in organic luminescent compounds to understand their molecular and bulk properties are of fundamental interest. In this thesis, NPI (1,8-naphthalimide) and BODIPY (boron-dipyrromethene) dyes were investigated to provide a broad overview of their structure-property correlations. Among commonly encountered organic luminescent materials, NPIs and BODIPYs have emerged as two broad classes of luminescent organic compounds, finding applications as functional luminescent materials in various fields. However, lack of understanding for controlling the cumulative emissive properties of these compounds has limited their usage as active solid-state emitters in various applications. This thesis presents several new insights into the molecular and bulk emissive properties of these two classes of luminescent dyes (NPIs and BODIPYs). The contents of the six chapters contained in this thesis are summarised below. Chapter 1 summarises the available understanding of the basic concepts of photoluminescence and the design strategies to develop solid-state luminescent and AIE (aggregation-induced emission) active materials. This chapter also emphasises in the basic nature of the NPI and BODIPY compounds, their substitution patterns and their inherent characteristics and touches upon the relatively unexplored properties of NPI and BODIPY based materials. The importance and scope of the work reported in the thesis is outlined at the end of the chapter. Chapter 2 describes a detailed investigation of a series of seven (4-oxoaryl substituted) NPI compounds (1-7) providing an insight into the molecular and cumulative photophysical behaviour of these compounds. The low ICT characteristics of the NPIs, coupled with the twisted geometry, facilitated solid-state luminescence in these materials. The solution and solid-state luminescent properties of these compounds can be directly correlated to their structural rigidity, nature of substituents and solid-state intermolecular interactions (e.g. π-π stacking, C-H•••O interactions etc.). The solid-state crystal structures of the NPI siblings are profoundly affected by the pendant substituents. All of the NPIs (1-7) show antiparallel dimeric π-π stacking interactions in the solid-state which can further extend in parallel, alternate, orthogonal or lateral fashion depending on the steric and electronic nature of the C-4′ substituents. Structural investigations including Hirsfeld surface analysis methods reveal that while strongly interacting systems show weak to moderate emission in their condensed states, weakly interacting systems show strong emission yields under the same conditions. The nature of packing and extended structures also affects the emission colors of the NPIs in the solid-state. DFT computational studies were utilized to understand the molecular and cumulative electronic behavior of the NPIs. Apart from the investigation of solid-state luminescence, other functional potentials of these NPIs were also explored. One of the compounds (i.e. 4) shows chemodosimetric response towards aqueous Hg(II) species with a ‘turn-on’ response. Also, depending on the molecular flexibility of the compounds, promising AIEE (aggregation-induced emission enhancement) features were observed in these NPIs. Later (in Chapter 3), we developed a systematic investigation in a series of purely organic NPIs, restricting various parameters, to attain a thorough understanding of such AIEE properties. Chapter 3 describes a detailed experimental and computational study in order gain an insight into the AIE (aggregation-induced emission) and AIEE mechanisms in NPI compounds. Systematic structural perturbation was used to fine tune the luminescence properties of three new 1,8-naphthalimides (8-10) in solution and as aggregates. The NPIs (8-10) show blue emission in solution state and the fluorescence quantum yields depend on their molecular rigidity. In concentrated solutions of the NPIs, intermolecular interactions were found to result in quenching of fluorescence. In contrast, upon aggregation (in THF:H2O mixtures), two of the NPIs show aggregation-induced-emission-enhancement (AIEE). The NPIs also show moderately high solid-state emission quantum yields (~10-12.7 %). The AIEE behaviors of the NPIs depend on their molecular rigidity and nature of intermolecular interactions. The NPIs (8-10) show different extents of intermolecular (π-π and C-H•••O) interactions in their solid-state structures depending on their substituents. Detailed photophysical, computational and structural investigations suggest that only an optimal balance of structural flexibility and intermolecular communication is the effective recipe for achieving AIEE characteristics in these NPIs. Chapter 4 presents the design, synthesis and detailed investigations and potential applications of a series of NPI-BODIPY dyads (11-13). The NPI and BODIPY moieties in these dyads are electronically separated by oxoaryl bridges and the compounds only differ structurally with respect to methyl substitutions on the BODIPY fluorophore. The NPI and BODIPY moieties retain their optical features in these molecular dyads (11- 13). Dyads 11-13 show dual emission in solution state originating from the two separate fluorescent units. The variations of the dual emission in these compounds are controlled by the structural flexibility of the systems. The dyads also show significant AIES (Aggregation-Induced-Emission Switching) features upon formation of nano-aggregates in THF-H2O mixtures with visual changes in emission from green to red color. Whereas the flexible and aggregation prone system (i.e. compound 11) shows aggregation-induced enhancement of emission, rigid systems with less favorable intermolecular interactions (i.e. compound 12-13) show aggregation-induced quenching of emission. The emission-intensity vs. the structural-flexibility correlations were found to be reverse in solution and aggregated states. Photophysical and structural investigations suggest that the intermolecular interactions (e.g. π-π stacking etc.) play major role in controlling emission of these compounds in aggregated states. Similar trends were also observed in the solid-state luminescence of these compounds. The applications of the luminescent dyads 11-13 as live-cell imaging dyes was also investigated. Chapter 5 describes investigations of photophysical properties of a series of six BODIPY dyes (14-19) in which there is a systematic alteration of a common -C6H4Si(CH3)3 substituent. Inrelated constitutional isomers, the systematic increment of steric congestion and lowering of molecular symmetry around the BODIPY core result in a steady increment of solution and solid- state fluorescence quantum yields. The increasing fluorescence quantum yields (solution, solid state) with increasing steric congestions show that the molecular free rotation and aggregation-induced fluorescence quenching of BODIPYs can be successfully suppressed by lowering the flexibility of the molecules. Photophysical and DFT investigations reveal that the electronic band gap in any set of these constitutional isomers remain almost similar. However, the crystal structures of the compounds reveal that the solid-state colour and quantum yields of the compounds in solid-state are also related to the nature of intermolecular interactions. Chapter 6 demonstrates the use of DFT computational methods to understand the effect of alkyl groups in governing the basic structural and electronic aspects of BODIPY dyes. As demonstrated in Chapter 4 and Chapter 5, apparently electronically inactive alkyl groups can be of immense importance to control the overall photophysics of BODIPYs. In this context, a systematic strategy su was utilized considering all possible outcomes of constitutionally-isomeric molecules to understand the effects of alkyl groups on the BODIPY molecules. Four different computational methods were employed to ascertain the unanimity of the observed trends associated with the molecular properties. In line with experimental observations, it was found that alkyl substituents in BODIPY dyes situated at 3/5-positions effectively participate in stabilization as well as planarization of such molecules. Screening of all the possible isomeric molecular systems was used to understand the individual properties and overall effects of the typical alkyl substituents in controlling several basic properties of such BODIPY molecules.
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33

Carlos, Carlota Pereira de Almeida. "Advanced optical spectroscopy of new materials for luminescent solar concentrators". Master's thesis, 2019. http://hdl.handle.net/10773/29191.

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The transition from the current energy matrix towards an environmentally friendly and a ordable energy sources is a crucial challenge of the 21st century. Fully energetically sustainable architecture is a strategic focus in this e ort, through the realisation of so-called net-zero energy buildings. This implies an increase in the use of renewable resources, such as the wind, tides and the sun. Hence, new technologies that integrate solar-harvesting devices into existing and newly constructed buildings are of growing relevance. Luminescent solar concentrators consist of a transparent matrix doped or coated with active optical centres that absorb the incident solar radiation, which is reemitted at a speci c wavelength and transferred by total internal re ection to the edges, where photovoltaic cells are located. This con guration enables photovoltaic devices to be embedded in building facades or windows, allowing them to be transformed into energy harvesting units. Challenges for the luminescent species in luminescent solar concentrators include the use of sustainable, natural-based organic molecules. In this scope, semitransparent amine-functionalized organic{inorganic hybrids (ureasils) incorporating two di erent natural-based organic dyes, chlorophyll and enhanced uorescent protein (eGFP), were synthesised and processed as thin lms and monoliths. The natural dyes' and organic-inorganic hybrid's excited state dynamics were studied and characterised { the absorption bands of chlorophyll a and eGFP were identi ed, as well as their characteristic emission in the red/NIR (600-750 nm) and visible (450-600 nm) spectral regions, respectively. The emission properties were further quanti ed through absolute emission quantum yield measurements, with the maximum values measured for the eGFP-doped di-ureasil hybrid (0:33 0:03) being two times higher than the maximum value found for the chlorophyll-doped hybrid samples (0:15 0:02). Fluorescent lifetime analysis was also performed resorting to two di erent techniques: time-correlated single photon counting and spectrally-resolved streak imaging, yielding uorescent emission lifetimes of 5 ns for chlorophyll and 2-3 ns for enhanced green uorescent protein, in solution and when incorporated into the hybrid hosts. Further analysis was carried out by tting a two exponential decay model to the uorescent decay curves of the for the green uorescent protein samples, considering that two distinct electronic states are responsible for the absorption around 488 nm and the emission at 510 nm. Based on the intriguing photoluminescent features of the dye-based samples, two prototypes of luminescent solar concentrators were fabricated and optically characterised. In particular, a liquid planar luminescent solar concentrator based on a glass container lled with eGFP dispersed in an aqueous solution and a eGFPdoped di-ureasil hybrid bulk planar luminescent solar concentrator. The devices were coupled to a silicon-based commercial PV device, revealing maximum optical conversion e ciencies of 2:99 0:01% (liquid) and 3:70 0:06% (bulk), illustrating the potential of this approach for the development of nature-based luminescent solar concentrators, meeting the requirements of reliable, sustainable and competitive energy systems.
A transição da matriz energética atual para fontes de energia competitivas de baixo impacto ambiental é uma problemática central no século XXI. A arquitetura energeticamente sustentável é um ponto estratégico nesse esforço, através da realização dos chamados edifícios de energia zero. Por defenição, estes edifícios fazem uso de sistemas de produção de energia renovável local, como por exemplo a fotovoltaica, para satisfazer as suas necessidades energéticas. Assim, novas tecnologias que integrem dispositivos de coleção de energia solar em edifícios existentes ou recémconstruídos são de crescente relevância. Os concentradores solares luminescentes são dispositivos compostos por uma matriz transparente com centros óticos ativos incorporados. Estes absorbem a radiação incidente, que é posteriormente reemitida com um comprimento de onda específico e transportada por reflexão interna total até à célula fotovoltaica localizada nas extremidades da matriz. Esta configuração permite a produção de dispositivos fotovoltaicos incorporados em fachadas de edifícios e janelas, permitindo que estes sejam transformados em unidades de produção de energia. Atualmente, um dos desafios na áreas dos concentradores solares luminescentes é a incorporação de moléculas orgânicas naturais como centros óticos. Neste âmbito, foram fabricados e processados híbridos orgânico-inorgânicos semitransparentes, denominados por ureiasils, modificados por dois corantes orgânicos naturais, clorofila e proteína verde fluorescente (eGFP). A dinâmica entre os estados excitados dos corantes naturais e da matriz híbrida foi estudada e caracterizada - foram identifícadas as bandas de absorção da clorofila a e da eGFP, assim como a sua emissão característica no vermelho/infravermelho próximo (600-750 nm) e na região do visível (450-600 nm), respetivamente. As propriedades de emissão foram quantificadas através de medidas de rendimento quântico absoluto, registando-se um valor máximo para o híbrido com eGFP incorporada (0,33+/-0,03) duas vezes superior ao encontrado para as matrizes híbridas dopadas com clorofila (0,15+/-0,02). Foram também analisados os tempos de vida dos emissão dos estados excitados das várias amostras, tendo sido encontrados valores ~5 ns para a clorofila e ~2-3 ns para a eGFP, em solução ou quando incorporadas nas matrizes híbridas. Procedeu-se ainda a uma análise mais aprofundada no caso das amostras com eGFP, através da aplicação de um modelo bi-exponencial às curvas de decaimento, uma vez que o modelo eletrónico da mesma indica a presença de dois estados excitados distintos responsáveis pela absorção em torno dos 488 nm e emissão a 510 nm. Devido às características fotoluminescentes interessantes das amostras à base de corantes naturais para aplicações em concentradores solares luminescentes, foram fabricados e caracterizados dois protótipos com geometria planar { um concentrador solar luminescente baseado num recipiente de vidro cheio com eGFP em solução aquosa, e um outro concentrador que consistia num monolito da matriz híbrida dopada com eGFP. Os dispositivos foram acoplados a uma célula fotovoltaica comercial de silício, revelando eficiências óticas de conversão máximas de 2; 99+/-0; 01% e 3; 70+/-0; 06%, respetivamente, ilustrando o potencial desta abordagem para o desenvolvimento de sistemas energéticos sustentáveis e competitivos.
Mestrado em Engenharia Física
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34

Brunner, Pierre-Louis Marc. "Towards polypeptides bearing luminescent side-chains as materials for organic light-emitting devices". Thesis, 2000. http://hdl.handle.net/2429/11218.

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Two different routes, using the Wittig reaction to obtained compound 2.5 are described. The O-benzyl-N-CBZ-L-serine cyclohexyl ammonium salt (2.7b) and the OstilbeneTN- CBZ-L-serine cyclohexyl ammonium salt (2.8b) were then prepared by coupling benzyl bromide or compound 2.5 respectively to iV-CBZ-Z-serine, as precursors to novel polypeptides containing a conjugated chromophore as a side-chain. Compound 2.9 was also obtained as a side-product by elimination of the side-chain in a basic media. The route toward these new materials involved the synthesis of the corresponding NCAs of 2.7b and 2.8b. Three different routes using SOCl₂ , Oxalyl chloride or PBr3 as halogenating agents were tried in an attempt to form the 5-membered ring of the NCAs from 2.7a, 2.7b and 2.8b. It was shown that the vinylic bond of the PPV oligomer-like side-chain of 2.8b got chlorinated when SOCI2 was used to form compound 2.11. Attempted syntheses of the polypeptides 2.12a and 2.12b using 4- methylmorpholine or diisopropylamine as initiator are also described. The photoisomerisation of 2.8a and 2.8b were explored. Excitation at 300 nm lead to a 57% conversion of the trans isomer to the cis isomer of the stilbene-like sidechain, where a broader excitation at wavelength greater than 290 nm lead to a 10 % conversion of the trans isomer to the cis isomer of the stilbene-like side-chain.
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35

Gurge, Ronald Matthew. "Synthesis and luminescent properties of new conjugated polymers based on poly(p-phenylene vinylene)". 1998. https://scholarworks.umass.edu/dissertations/AAI9841877.

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The "push-pull" electronically substituted polymers poly(2 (5) -bromo-5 (2) -n-hexyloxy-1,4-phenylene vinylene), poly(2 (5) -chloro-5 (2) -n-hexyloxy-1,4-phenylene vinylene) and poly(2 (5) -fluoro-5 (2) -n-hexyloxy-1,4-phenylene vinylene) were synthesized by a soluble precursor method and were used to fabricate light emitting diode (LED) devices. Thermal elimination of the polyether precursors gives final conjugated polymers as flexible red films. Precursor polymers can be spin-cast from solutions onto indium/tin oxide (ITO) pretreated quartz plates, then thermally converted to the final red polymers. Light emitting diode fabrication is then completed by the thin film vapor deposition of calcium, followed by aluminum. LED devices of the "push-pull" polymers give light emission in the 620-635 nm range. Two fluorinated polymers, poly(2-fluoro-1,4-phenylene vinylene) and poly(2,5-difluoro-1,4-phenylene vinylene) were investigated for their electroluminescent (EL) properties. LED's using these materials as emissive layers show substantial EL wavelength shifts (560 nm and 600 nm, respectively) relative to emission from unsubstituted poly(1,4-phenylene vinylene) (565 nm). These differences in EL emission can be attributed to the electronic effects of fluorine substitution. Synthetic strategies were developed for copolymeric materials based on poly(1,4-phenylene vinylene). The alternating block copolymer, poly (1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene- 3,5-dimethoxy-1,4-phenylene) was synthesized by a modified Wittig polymerization utilizing trialkyl phosphonium salts. This resulted in a regiospecific trans-olefination reaction when compared to polymeric materials synthesized through the use of common triaryl-phosphonium salts. Harsh post-Wittig isomerization procedures using I$\sb2$ were bypassed as a result of the high trans-cis ratio of the final copolymer. It was fully characterized using the standard spectroscopic techniques as well as elemental analysis. Light-emitting single-layer diodes using the soluble, processible copolymer as the emitting layer gives green light with an electroluminescence maximum at 513 nm.
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36

Su, Yu-Min, i 蘇裕閔. "Synthesis of Blue Luminescent Materials Consist of Naphthalene Derivative with Application to Organic Light Emitting Diodes". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9a835n.

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碩士
國立中山大學
光電工程學系研究所
107
Organic luminescent materials play on important role in lighting and display today. Blue light is one of the key elements to make full-color organic light-emitting diodes. However, there are still challenges in electroluminescence, including efficiency, color purity, stability, etc. So it has become a hot field of research. In this reaseach, blue organic luminescent materials, PA, POA and CzP were successfully developed and their thermal stabilities, photophysical properties, and electroluminescence performances were investigated. Three synthesized molecules were designed consisting of host combined with guest. We chose Naphthalene derivatives and Carbazole as the host and Anthracene derivatives as the guest. The sterically hindered structure and ether group were used to retain the luminescent properties of the materials while approached the suitable bandgap by changing the energy level of the synthesis. The compounds were confirmed by 1H NMR and mass data. The Td5% were higher than 455°C and the Tg were between 190°C to 200°C which exhibited a good thermally stability. In the film state, PA, POA and CzP showed the absorption wavelength maximum in the range of 322 to 394 nm, whereas the emission wavelengths maximum showed 448, 438 and 404 nm, respectively. These materials could also emit stable blue light. To explore the EL performances of three synthesized molecules, these fluorophores were applied as an emitting layer to fabricate non-doped oled diodes. The EL device structure is ITO/NPB(40nm)/EML(30nm)/TPBi(30nm)/LiF(1nm)/Al(100nm). A OLED based on PA exhibited the better performance with the turn on voltage of 4.5V, brightness of 8221cd/m2, current efficiency of 1.13cd/A and external quantum efficiency of 0.65%. In terms of light color, the CzP device emited excellent blue light with CIE coordinates of (0.16, 0.08).
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37

Chatterjee, Sayantan. "Hybrid Nanostructured Materials from Bile Acid Derived Supramolecular Gels". Thesis, 2017. http://etd.iisc.ac.in/handle/2005/3699.

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Research activities towards the self-assembly of small organic molecules building blocks which lead to form supramolecular gel has increased extensively during the past two decades. The fundamental investigations of the morphological properties and the mechanical properties of these supramolecular gels are crucial for understanding gelation processes. Most supramolecular gelators were discovered by serendipity, but nowadays ratiional design of new gelators has become somewh at feasible. As a consequence, an increasing number of multi stimuli-responsive and functional molecular gels are reported, offering great prospects with myriads of applications includ ing drug delivery and smart materials as shown in scheme 1. Scheme 1 Part 2: Synthesis of semiconductor nanocrystals In the last two decades, the synthetic development of semiconductor col loidal nanocrystals has been extended from the adjustment of their size, shape, and composition of the particles at the molecular level. Such adjustments of nanocrystals at the molecula r level might open different fields of applications in materials and biological sciences. I n this chapter, the concept of the shape contr ol synthesis of colloidal nanocrystals with a narrow size distribution, and the synthesis of composition dependent alloy type mat erials are described (Scheme 2). Scheme 2 Chapter 2: Synthesis of luminescent semiconductor nanocrystals Part 1: Cadmium deoxycholate: a new and efficient precursor for high ly luminescent CdSe nanocrystals This part demonstrates the sy nthesis of Cadmium deoxycholate (CdDCh2), an efficient Cd-precursor for the synthesis of high quality, monodisperse, multi color emittting CdSe Scheme 3 nanocrystals, while maintaining their high photoluminescent quantum efficiency (Scheme 3). The high thermal stability of CdDCh2 (decomposition temperature: 332 °C) was utilized to achieve high injection and growth temperatures (∼300 °C) for the syntheesis of red emitting nanocrystals with a sharp f ull width at half maximum (FWHM) and multiple excitonic absorption features. We believe that CdDCh2 can be useful for the prreparation of other nanomaterials such as CdS, CdTe and CdSe@CdS core-shell QDs. Part 2: Ligand mediated exccited state carrier relaxation dynamics of Cd1-xZnxSe1-ySy NCs derived from bile salts Bile salts of Cadmium and Zinc provide a convenient and inexpensive single step synthetic route for highly photoluminescent and stable semiconductor nanocrystals (NCs). The high thermal stabilities of Cadmium and Zinc deoxycholates (CdDCh2 and ZnDCh2) allowed us to fine-tune the synthesis of the NCs at high temperatures while maintaining the monodispersity, crystallinity and reproducibility (Scheme 4). Organic capping agent induced lattice strain affects the excited Scheme 4 state relaxation processes of the NCs. The analysis of photoluminescence decay profiles revealed that the average lifettime decreased with the increasing lattice strain of the NCs. A kinetic stochastic model of photoexcited carrier relaxation dynamics of NCs was employed to estimate the values of the radiative recombination rates, the photoluminescence quenching rates and the non-radiative recombination rates of the NCs. These data showed that the non-radiative relaxation rates and the numbeer of surface trap states increased with the incrreasing lattice strain of the NCs. Such types of NCs can have great potential in nonlinear optics, photocatalysis and solar cells. Chapter 3: Synthesis of organic-inorganic hybrid materials Part 1: Hierarchical self-assembly of photoluminescent CdS nanoparticles into bile acid derived organogel: morphological and photophysical properties In this part a strategy towards integrating photoluminescent semiconductor nanoparticles into a bio-surfactant derived organoggel has been reported. A facially amphiphilic bile thiol was used for capping CdS nanoparticless (NPs) which were embedded in a gel derived from a new bile acid organogelator in order to furnish a soft hybrid material (Scheme 5). The presence of CdS NPs in a well-ordered 1D array on the organogel network was confirmed using microscopic Scheme 5 techniques. Photophysical stuudies of the gel–NP hybrid revealed resolved excitation and emission characteristics. Time resolved spectroscopic studies showed that the average lifetime value of the CdS NPs increased in the gel state compared to the sol phase. A kinetic model was utilized to obtain quantitative information about the different decay pathways of the photoexcited NPs in the sol and gel states. Part 2: A novel strategy towards designing a CdSe quantum dot–metallohydrogel composite material This section describes an efficiient method to disperse hydrophobic CdSe quaantum dots (QDs) in an aqueous phase using cetyltriimethylammonium bromide (CTAB) micelles without any surface ligand exchange. The water soluble QDs were then embedded in the 3D self-assembled fibrillar networks (SAFINs) of a hydrogel showing homogeneous dispersibility as eviidenced by Scheme 6 optical and electron microscopico techniques (Scheme 6). The photophyssical studies of the hydrogel–QD from composite are reported for the first time. These composite materials may have potential applications in biology, optoelectronics, sensors, non-linear optics and materials science. Part 3: Photophysical aspectts of self-assembled CdSe QD-organogel hyybrid and its thermoresponsive properties A luminescent hybrid gel was constructed by incorporating CdSe quantuum dots (QDs) in a facially amphiphilic bile acid derived dimeric urea organogel throough non-covalent interaction between ligands capped on QDs surface and hydrophobic pockets of the gel (Scheme 7). The optical transparency of the hybrid materials and the dirrectionalities of the QDs in the gel medium were confirmed by photophysical and microscopic studies. The detailed excited state dynamics of the QD–organogel hybrid has been reported for the first time with the help of lifetime analysis and a kinetic decay model, and thee data revealed that the average lifetime of the QDs decreased in the gel medium. The reversible thermoresponsive behavior of the QD doped organogel was investigated by steady-state fluorescence spectroscopy. W e believe that the results obtained herein provides a route to develop a thermoresponsive system for practical application, especially because of the spatial assembly between soft organic scaffolds and colloidal QDs. Scheme 7 Part 4: In-situ formation of luminescent CdSe QDs in a metallohydrogel: a strategy towards synthesis, isolation, storage and re-dispersion of the QDs A one step, in-situ, room temperature synthesis of yellow luminesce nt CdSe QD was achieved in a metallohydrog el derived from a facially amphiphilic bile salt, resulting in a QD-gel hybrid (Scheme 8). T he ordered self-assembly and homogeneous distribution of the CdSe QDs in the hydrogel network was observed from optical and electro n micrographs. The different excited state behav iors of the hybrid were revealed for the fir st time using time resolved spectroscopy. Ad ditionally, we described the successful isolation of the photoluminescent CdSe QDs from the gel followed by their re-dispersion in an organic solvent using suitable capping ligands. Scheme 8 Chapter 4: Facially a mphiphilic bile acid derived meta llohydrogel: an efficient template for th e enantioselective Diels-Alder reactio n An enantioselective Diels-Ald er reaction mediated by a facially amphiphilic bile acid derived metallogel scaffold has been a chieved (Scheme 9). Different hydrophobic domains present in Scheme 9 the gel appear to facilitate the enantioselective reaction. Various spectro scopic and electron microscopic techniques were employed to understand the possible reasons for the stereoselectivity in the gel. Subsequently, different counter anion s dependent rate accelerations and induced enantioselectivity in the ZnCh2 gel were studied in detail. These preliminary results of the non-covalent based supramolecular heterogeneous catalysis offer new possibilities for using metallogels as nanoreactors for different stereoselective reactions.
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38

Chatterjee, Sayantan. "Hybrid Nanostructured Materials from Bile Acid Derived Supramolecular Gels". Thesis, 2017. http://etd.iisc.ernet.in/2005/3699.

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Research activities towards the self-assembly of small organic molecules building blocks which lead to form supramolecular gel has increased extensively during the past two decades. The fundamental investigations of the morphological properties and the mechanical properties of these supramolecular gels are crucial for understanding gelation processes. Most supramolecular gelators were discovered by serendipity, but nowadays ratiional design of new gelators has become somewh at feasible. As a consequence, an increasing number of multi stimuli-responsive and functional molecular gels are reported, offering great prospects with myriads of applications includ ing drug delivery and smart materials as shown in scheme 1. Scheme 1 Part 2: Synthesis of semiconductor nanocrystals In the last two decades, the synthetic development of semiconductor col loidal nanocrystals has been extended from the adjustment of their size, shape, and composition of the particles at the molecular level. Such adjustments of nanocrystals at the molecula r level might open different fields of applications in materials and biological sciences. I n this chapter, the concept of the shape contr ol synthesis of colloidal nanocrystals with a narrow size distribution, and the synthesis of composition dependent alloy type mat erials are described (Scheme 2). Scheme 2 Chapter 2: Synthesis of luminescent semiconductor nanocrystals Part 1: Cadmium deoxycholate: a new and efficient precursor for high ly luminescent CdSe nanocrystals This part demonstrates the sy nthesis of Cadmium deoxycholate (CdDCh2), an efficient Cd-precursor for the synthesis of high quality, monodisperse, multi color emittting CdSe Scheme 3 nanocrystals, while maintaining their high photoluminescent quantum efficiency (Scheme 3). The high thermal stability of CdDCh2 (decomposition temperature: 332 °C) was utilized to achieve high injection and growth temperatures (∼300 °C) for the syntheesis of red emitting nanocrystals with a sharp f ull width at half maximum (FWHM) and multiple excitonic absorption features. We believe that CdDCh2 can be useful for the prreparation of other nanomaterials such as CdS, CdTe and CdSe@CdS core-shell QDs. Part 2: Ligand mediated exccited state carrier relaxation dynamics of Cd1-xZnxSe1-ySy NCs derived from bile salts Bile salts of Cadmium and Zinc provide a convenient and inexpensive single step synthetic route for highly photoluminescent and stable semiconductor nanocrystals (NCs). The high thermal stabilities of Cadmium and Zinc deoxycholates (CdDCh2 and ZnDCh2) allowed us to fine-tune the synthesis of the NCs at high temperatures while maintaining the monodispersity, crystallinity and reproducibility (Scheme 4). Organic capping agent induced lattice strain affects the excited Scheme 4 state relaxation processes of the NCs. The analysis of photoluminescence decay profiles revealed that the average lifettime decreased with the increasing lattice strain of the NCs. A kinetic stochastic model of photoexcited carrier relaxation dynamics of NCs was employed to estimate the values of the radiative recombination rates, the photoluminescence quenching rates and the non-radiative recombination rates of the NCs. These data showed that the non-radiative relaxation rates and the numbeer of surface trap states increased with the incrreasing lattice strain of the NCs. Such types of NCs can have great potential in nonlinear optics, photocatalysis and solar cells. Chapter 3: Synthesis of organic-inorganic hybrid materials Part 1: Hierarchical self-assembly of photoluminescent CdS nanoparticles into bile acid derived organogel: morphological and photophysical properties In this part a strategy towards integrating photoluminescent semiconductor nanoparticles into a bio-surfactant derived organoggel has been reported. A facially amphiphilic bile thiol was used for capping CdS nanoparticless (NPs) which were embedded in a gel derived from a new bile acid organogelator in order to furnish a soft hybrid material (Scheme 5). The presence of CdS NPs in a well-ordered 1D array on the organogel network was confirmed using microscopic Scheme 5 techniques. Photophysical stuudies of the gel–NP hybrid revealed resolved excitation and emission characteristics. Time resolved spectroscopic studies showed that the average lifetime value of the CdS NPs increased in the gel state compared to the sol phase. A kinetic model was utilized to obtain quantitative information about the different decay pathways of the photoexcited NPs in the sol and gel states. Part 2: A novel strategy towards designing a CdSe quantum dot–metallohydrogel composite material This section describes an efficiient method to disperse hydrophobic CdSe quaantum dots (QDs) in an aqueous phase using cetyltriimethylammonium bromide (CTAB) micelles without any surface ligand exchange. The water soluble QDs were then embedded in the 3D self-assembled fibrillar networks (SAFINs) of a hydrogel showing homogeneous dispersibility as eviidenced by Scheme 6 optical and electron microscopico techniques (Scheme 6). The photophyssical studies of the hydrogel–QD from composite are reported for the first time. These composite materials may have potential applications in biology, optoelectronics, sensors, non-linear optics and materials science. Part 3: Photophysical aspectts of self-assembled CdSe QD-organogel hyybrid and its thermoresponsive properties A luminescent hybrid gel was constructed by incorporating CdSe quantuum dots (QDs) in a facially amphiphilic bile acid derived dimeric urea organogel throough non-covalent interaction between ligands capped on QDs surface and hydrophobic pockets of the gel (Scheme 7). The optical transparency of the hybrid materials and the dirrectionalities of the QDs in the gel medium were confirmed by photophysical and microscopic studies. The detailed excited state dynamics of the QD–organogel hybrid has been reported for the first time with the help of lifetime analysis and a kinetic decay model, and thee data revealed that the average lifetime of the QDs decreased in the gel medium. The reversible thermoresponsive behavior of the QD doped organogel was investigated by steady-state fluorescence spectroscopy. W e believe that the results obtained herein provides a route to develop a thermoresponsive system for practical application, especially because of the spatial assembly between soft organic scaffolds and colloidal QDs. Scheme 7 Part 4: In-situ formation of luminescent CdSe QDs in a metallohydrogel: a strategy towards synthesis, isolation, storage and re-dispersion of the QDs A one step, in-situ, room temperature synthesis of yellow luminesce nt CdSe QD was achieved in a metallohydrog el derived from a facially amphiphilic bile salt, resulting in a QD-gel hybrid (Scheme 8). T he ordered self-assembly and homogeneous distribution of the CdSe QDs in the hydrogel network was observed from optical and electro n micrographs. The different excited state behav iors of the hybrid were revealed for the fir st time using time resolved spectroscopy. Ad ditionally, we described the successful isolation of the photoluminescent CdSe QDs from the gel followed by their re-dispersion in an organic solvent using suitable capping ligands. Scheme 8 Chapter 4: Facially a mphiphilic bile acid derived meta llohydrogel: an efficient template for th e enantioselective Diels-Alder reactio n An enantioselective Diels-Ald er reaction mediated by a facially amphiphilic bile acid derived metallogel scaffold has been a chieved (Scheme 9). Different hydrophobic domains present in Scheme 9 the gel appear to facilitate the enantioselective reaction. Various spectro scopic and electron microscopic techniques were employed to understand the possible reasons for the stereoselectivity in the gel. Subsequently, different counter anion s dependent rate accelerations and induced enantioselectivity in the ZnCh2 gel were studied in detail. These preliminary results of the non-covalent based supramolecular heterogeneous catalysis offer new possibilities for using metallogels as nanoreactors for different stereoselective reactions.
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39

Pandey, Umesh Pratap. "New Class of Tricoordinate Boron Based Donor-Acceptor (D-A) Systems Exhibiting External Stimuli Responsive Properties, Delayed Emission and Room Temperature Phosphorescence". Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4457.

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The main thrust of this thesis is the design and development of a new class of boron-based acceptors, with a substituent which maintains good electronic coupling between boron and the other substitutes on boron, without sacrificing the overall stability of the compound and to investigate their photophysical properties and applications
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40

Chowdhury, Aniket. "Vinylanthracene and Triphenylamine Based Luminescent Molecular Systems : From Aggregation-Induced Emission to Explosive Detection". Thesis, 2016. http://etd.iisc.ac.in/handle/2005/2968.

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In the last few years, considerable efforts have been given to develop sensitive and effective sensors for explosive materials and to generate systems which exhibit high luminescence in both solution and solid-state. The increasing number of terrorist activities around the world have prompted scientists to design effective ways to detect and disarm even the trace amount of explosives. The nitroaromatics (NACs) are the common constituents of most of the explosives due to high explosive velocity and ease of availability. The NACs were extensively used as the main constituents in landmines until World War II. Apart from their explosive behavior, the NACs are well-known environmental pollutants. The industrial waste and the leakages from unexploded landmines are the major contributors towards the soil and ground water contamination. Presently for effective detection of trace amount of explosives, skilled canines and metal based detectors are commonly used. The canines are trained for a specific type of explosives which limit their ability to detect different types of substrates. The chemical sensors that work on the principle of colorimetric and/or fluorimetric detection techniques have emerged as suitable alternative due to cheap production cost, portability and sensitivity. Different types of materials including conjugated polymers, metal-organic frameworks (MOFs), and quantum-dots have been reported as efficient chemosensors for NACs. However, poor solubility in the common organic solvents, low solid-state fluorescence, very high molecular weight and lack of signal amplification have restricted the application of these material for in-field testing. Renewed interests have been invested in small molecule based systems; and metal-organic discrete molecular architectures due to precise control over their photophysical properties and the supramolecular interaction among neighboring molecules that facilitates energy migration among the molecular backbone. On the other hand, recently post-synthetic modification of different molecular systems including MOFs and polymers has emerged as a potential technique to incorporate desired functional groups into the system and to tune their properties with the retention of basic structures. Reports on the post-synthetic modification of discrete metal-organic architectures are rare due to the delicate nature of the metal-organic bonds that ruptures on mild environmental changes. Therefore, post-synthetic functionalization of discrete molecular systems using mild reaction conditions will open up a myriad of possibilities to generate new systems with desired characteristics. Chapter 1 of the thesis will briefly discuss the history of different explosive materials including different detection methodologies that are widely used. It will also include a brief discussion on different small molecular systems with high solid-state luminescence. In Chapter 2, design and synthesis of triphenylamine-based two Platinum(Pt)(II) molecules functionalized with carboxylic acid and ester groups including their organic analogues have been discussed. The triphenylamine core was chosen due its unique non-planarity and luminescence. On the other hand, Pt(II) center was incorporated to increase intermolecular spacing in solid-state that can induce high luminescence. Scheme 1. Schematic representation of fluorescence quenching using small molecules. All the four molecules were found to be highly sensitive towards NACs including picric acid and dinitrophenol. Although the molecules exhibited similar sensitivity in solution, the carboxylic acid analogues demonstrated superior sensitivity in solid-state. Careful observation of the crystal structures of the systems revealed the acid analogues were oriented in a 2-D grid-like pattern that facilitated energy migration among neighboring molecules (Scheme 1.). Chapter 3 describes design, synthesis, and NACs sensing behavior of anthracene-based four purely organic small molecules. The molecules exhibited high selectivity towards picric acid only. All the molecules were found to be highly emissive in both solution and solid-state due to the vinylanthracene backbone (Scheme 2.). Scheme 2. Schematic representation of fluorescence quenching and solid-state sensing behavior. Chapter 4 discusses the strategy to develop mechano-fluorochromic and AIE active triphenylamine-based Pt(II) complex and its organic analogue. The twisted triphenylamine backbone restricted molecular close packing in solid-state; and weak C-H-- interactions were utilized to hinder the motion of the phenyl rings. As a result, the molecules were highly emissive in solid-state. Grinding disrupted the intermolecular interactions and thus mechano-fluorochromic behavior was observed. Due to twisted backbone, the molecules were also found to be AIE active. Both the systems containing terminal aldehyde groups were finally utilized for selective detection of biomolecule cysteine (Scheme 3.). Scheme 3. Mechano-fluorochromic and AIE behavior of the triphenylamine based Pt(II) complex. In Chapter 5 vinylanthracene-based linear donor was used in combination with carbazole-based 90° and triphenylamine-based 120° Pt(II) acceptors to generate (4+4) and (6+6) molecular squares and hexagons, respectively. The vinylanthracene backbone imparts high solution and solid-state luminescence to the system as well as made them AIE active. The molecules were further investigated for the solution and solid-state sensing for NACs and found to be effective for trinitrotoluene (TNT) and dinitrotoluene (DNT) (Scheme 4.). Scheme 4. Schematic representation of AIE active molecular square and its NACs sensing. Chapter 6 describes the formation of Pd3 self-assembled molecular trinuclear barrels containing triphenylamine imidazole donors and Pd(II) acceptors. Using Knoevenagel condensation the aldehyde group present in the barrel was post-synthetically functionalized with Meldrum’s acid. From spectroscopic characterization, it was proved that the structural integrity remained intact after the post-modification treatment (Scheme 6.). Surprisingly, pre-synthetic modification of the donor alone with Meldrum’s acid followed by self-assembly treatment with the Pd(II) ion did not yield trigonal barrel 6.8. Scheme 6. Post-synthetic functionalization of trinuclear barrels using Knoevenagel condensation.(For colour pictures pl see the abstract pdf file)
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41

Chowdhury, Aniket. "Vinylanthracene and Triphenylamine Based Luminescent Molecular Systems : From Aggregation-Induced Emission to Explosive Detection". Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2968.

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In the last few years, considerable efforts have been given to develop sensitive and effective sensors for explosive materials and to generate systems which exhibit high luminescence in both solution and solid-state. The increasing number of terrorist activities around the world have prompted scientists to design effective ways to detect and disarm even the trace amount of explosives. The nitroaromatics (NACs) are the common constituents of most of the explosives due to high explosive velocity and ease of availability. The NACs were extensively used as the main constituents in landmines until World War II. Apart from their explosive behavior, the NACs are well-known environmental pollutants. The industrial waste and the leakages from unexploded landmines are the major contributors towards the soil and ground water contamination. Presently for effective detection of trace amount of explosives, skilled canines and metal based detectors are commonly used. The canines are trained for a specific type of explosives which limit their ability to detect different types of substrates. The chemical sensors that work on the principle of colorimetric and/or fluorimetric detection techniques have emerged as suitable alternative due to cheap production cost, portability and sensitivity. Different types of materials including conjugated polymers, metal-organic frameworks (MOFs), and quantum-dots have been reported as efficient chemosensors for NACs. However, poor solubility in the common organic solvents, low solid-state fluorescence, very high molecular weight and lack of signal amplification have restricted the application of these material for in-field testing. Renewed interests have been invested in small molecule based systems; and metal-organic discrete molecular architectures due to precise control over their photophysical properties and the supramolecular interaction among neighboring molecules that facilitates energy migration among the molecular backbone. On the other hand, recently post-synthetic modification of different molecular systems including MOFs and polymers has emerged as a potential technique to incorporate desired functional groups into the system and to tune their properties with the retention of basic structures. Reports on the post-synthetic modification of discrete metal-organic architectures are rare due to the delicate nature of the metal-organic bonds that ruptures on mild environmental changes. Therefore, post-synthetic functionalization of discrete molecular systems using mild reaction conditions will open up a myriad of possibilities to generate new systems with desired characteristics. Chapter 1 of the thesis will briefly discuss the history of different explosive materials including different detection methodologies that are widely used. It will also include a brief discussion on different small molecular systems with high solid-state luminescence. In Chapter 2, design and synthesis of triphenylamine-based two Platinum(Pt)(II) molecules functionalized with carboxylic acid and ester groups including their organic analogues have been discussed. The triphenylamine core was chosen due its unique non-planarity and luminescence. On the other hand, Pt(II) center was incorporated to increase intermolecular spacing in solid-state that can induce high luminescence. Scheme 1. Schematic representation of fluorescence quenching using small molecules. All the four molecules were found to be highly sensitive towards NACs including picric acid and dinitrophenol. Although the molecules exhibited similar sensitivity in solution, the carboxylic acid analogues demonstrated superior sensitivity in solid-state. Careful observation of the crystal structures of the systems revealed the acid analogues were oriented in a 2-D grid-like pattern that facilitated energy migration among neighboring molecules (Scheme 1.). Chapter 3 describes design, synthesis, and NACs sensing behavior of anthracene-based four purely organic small molecules. The molecules exhibited high selectivity towards picric acid only. All the molecules were found to be highly emissive in both solution and solid-state due to the vinylanthracene backbone (Scheme 2.). Scheme 2. Schematic representation of fluorescence quenching and solid-state sensing behavior. Chapter 4 discusses the strategy to develop mechano-fluorochromic and AIE active triphenylamine-based Pt(II) complex and its organic analogue. The twisted triphenylamine backbone restricted molecular close packing in solid-state; and weak C-H-- interactions were utilized to hinder the motion of the phenyl rings. As a result, the molecules were highly emissive in solid-state. Grinding disrupted the intermolecular interactions and thus mechano-fluorochromic behavior was observed. Due to twisted backbone, the molecules were also found to be AIE active. Both the systems containing terminal aldehyde groups were finally utilized for selective detection of biomolecule cysteine (Scheme 3.). Scheme 3. Mechano-fluorochromic and AIE behavior of the triphenylamine based Pt(II) complex. In Chapter 5 vinylanthracene-based linear donor was used in combination with carbazole-based 90° and triphenylamine-based 120° Pt(II) acceptors to generate (4+4) and (6+6) molecular squares and hexagons, respectively. The vinylanthracene backbone imparts high solution and solid-state luminescence to the system as well as made them AIE active. The molecules were further investigated for the solution and solid-state sensing for NACs and found to be effective for trinitrotoluene (TNT) and dinitrotoluene (DNT) (Scheme 4.). Scheme 4. Schematic representation of AIE active molecular square and its NACs sensing. Chapter 6 describes the formation of Pd3 self-assembled molecular trinuclear barrels containing triphenylamine imidazole donors and Pd(II) acceptors. Using Knoevenagel condensation the aldehyde group present in the barrel was post-synthetically functionalized with Meldrum’s acid. From spectroscopic characterization, it was proved that the structural integrity remained intact after the post-modification treatment (Scheme 6.). Surprisingly, pre-synthetic modification of the donor alone with Meldrum’s acid followed by self-assembly treatment with the Pd(II) ion did not yield trigonal barrel 6.8. Scheme 6. Post-synthetic functionalization of trinuclear barrels using Knoevenagel condensation.(For colour pictures pl see the abstract pdf file)
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42

Teng, Yu-Kuen, i 鄧育坤. "Properties of UV Light Crosslinkable Photo-Resistant Organic Luminescent Material". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/zr6ny4.

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碩士
國立臺北科技大學
有機高分子研究所
96
This research is the synthesis of photo-resistant organic luminescent material. The blue photo-resistant luminescent compound is consisted of phenylenes and oxetane function group synthesized via Suzuki coupling. These compounds with oxetane side groups which are soluble in proper solvent are spin-coated on the substrate to form thin films. It can be converted into patterned insoluble polymer films after UV light irradiation with proper photo-initiator adding and patterned mask attached. The solubility of irradiated films is different from non-irradiated part. It successfully produced a patterned picture. Those compounds were characterized with NMR, IR, Mass spectroscopy. The optic properties of the thin film were measured by UV-Vis spectroscopy and PL spectrometer.
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43

Li, Chi-shing, i 李祈興. "Study of Cathode Luminescence of Organic Lighting Material". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/65766891170350848172.

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碩士
義守大學
電子工程學系碩士班
93
This investigation presents a novel lighting method, the anode plate, which thermally evaporates the Alq3 organic green material onto Ito-glass ( 4000 A ). The cathode involves using the tungsten to heat the metal cathode to achieve emission of the electrons. The electrons are induced from the cathode to the anode, which accelerates with the electron field of vacuum. Additionally, the brightness of luminescence increases as an increasing number of electrons numbers arrive at the anode plate. When the anode voltage is 80V, the luminance reaches 97cd/m2. If the anode voltage exceeds 80V, the electrons move across the Alq3 and the remaining electron kinetic energy to accumulate in the anode plate and release with heat. After the thermal energy causes evaporation of Alq3, the anode plate finally cracks. While attempting to alleviate the damage incurred from electron kinetic energy and the heat from the cathode, this investigation also selects the audion owing to its excellent electron properties from thermal emission in order to place the organic anode plate on top of the gate and the cathode of the audion. Results obtain from luminescence are better than those obtained from an electronic gun, thus enabling a good cathode electron source to produce an adequate number of electrons to reach the anode plate. Furthermore, a higher electric current implies an enhanced luminescence performance of organic lighting materials.
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44

Shruthi, S. "Analytical Applications of Bile Acid-derived Soft Materials". Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5598.

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Supramolecular gels are soft materials with solid-like properties such as supporting weight and retaining shape; and some liquid-like features which make them injectable, printable, etc. On the other hand, lanthanide-based probes have been extensively used in analytical chemistry due to their unique and useful features such as sharp, line-like emission, long excited-state lifetimes, large Stokes shifts, antenna effect, etc. In this thesis, we have used supramolecular metallogels formed by integrating lanthanides with bile salts as a matrix for sensitive detection of natural antioxidants (gallate derived green tea polyphenols) and clinically important glycosidases. This work also presents a user-friendly, low-cost, and instrument-free approach to sensing these analytes using gel immobilized paper sensors with the potential to serve as a rapid test for detecting these analytes in real samples in resource limited areas.
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45

Kammoe, Astride Lorette. "Synthesis and Characterization of Multifunctional Organic/ inorganic Hybrid Materials obtained by the "wet chemistry" approach". Doctoral thesis, 2013. https://monarch.qucosa.de/id/qucosa%3A19272.

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Die vorliegende Arbeit fokussiert auf die Synthese von organisch/anorganischen Hybridmaterialien mit multifunktionalen Eigenschaften unter ausschliesslicher Darstellung dieser Materialen mit Hilfe des „wet chemistry“ Zugangs. Ausgehend von der Darstellung und Charakterisierung von isomorphen bzw. isostrukturellen Hybridmaterialien der allgemeinen Zusammensetzung catena-{[Me3NH][MCl3·2H2O]}n (Mtac) (MII = Mn, Co, Ni, Cu, tac = [Me3NH]Cl3·2H2O]) speziell mittels IR und UV/vis Spektroskopie ist beschrieben, wie sich aus diesen entsprechende bi-, tri-, und auch tetra-heterometallische Koordinationspolymere der allgemeinen Zusammenseztung {MxM´ytac}n, {MxM´yM´´ztac}n, {MxM´yM´´zM´´´ttac}n (MII = M ≠ M´≠ M´´≠ M´´´≠ M´´´´ und x, y, z, t als prozentualer Metallgehalt) herstellen lassen und welche limitierende Faktoren zu berücksichtigen sind. Leifähigkeitsmessungen an Einkristallen ausgewählter Koordinationspolymere werden vorgestellt. Zusätzlich werden die durch Rekristallisation von Nitac erhaltenen zwei verschiedenen Koordinationspolymere der Formel {[Me3NH]3{NiCl4}{NiCl3}}n und {[(Me3NH]{NiCl3}}n in Bezug auf ihre ungewöhnlichen strukturellen und magnetischen Eigenschaften vorgestellt und beschrieben. Die durch Austausch von [Me3NH]+ Kationen gegen [Et3NH]+ bzw. protonierten aromatischen N-haltigen Kationen wie [2,2’-bipyH2]2+, [4,4’-bipyH2]2+ and [1,10-phenH2]2+ erhaltenen Reaktionsprodukte aus Umsetzungen mit Hilfe des “wet chemistry” Zugangs werden im Hinblick auf ihre Festkörperstrukturen beschrieben. Die erfolgreiche Darstellung einer neuen Familie von perylentetracarboxylato-basierenden Komplexen, die teilweise hervorragende Löslichkeiten besitzen, wird beschrieben sowie die strukturellen, magnetischen und lumineszierenden Eigenschaften ausgewählter Vetreter.
The thesis presented here is focused on the synthesis of organic/ inorganic hybrid materials with multifunctional properties by means of the “wet chemistry” approach. The synthesis and characterization of hybrid materials with the general composition catena-{[Me3NH][MCl3·2H2O]}n (Mtac) (MII = Mn, Co, Ni, Cu, tac = [Me3NH]Cl3·2H2O]) is described. Due to their isomorphic and/ or isostructural character, bi-, tri-, and even tetra-heterometallic chains of the general formula {MxM´ytac}n, {MxM´yM´´ztac}n, {MxM´yM´´zM´´´ttac}n (MII = M ≠ M´≠ M´´≠ M´´´≠ M´´´´ and x, y, z, t is the percentage of each metal content) were synthesized and characterized. Limitating factors of the synthesis of these types of heterometallic coordination polymers are discussed. Furthermore, the conductive properties of selected representatives were investigated. Additionally, the products obtained from recrystallization of Nitac, two different novel 1D coordination polymers of the formula {[Me3NH]3{NiCl4}{NiCl3}}n and {[(Me3NH]{NiCl3}}n are described with respect to their structural and magnetic properties. Efforts to replace the [Me3NH]+ cations of Mtac compounds by [Et3NH]+ cations as well as by protonated aromatic amines as [2,2’-bipyH2]2+, [4,4’-bipyH2]2+ and [1,10-phenH2]2+ are reported next with respect to the structural exploration of obtained hybrid materials by the “wet chemistry” approach. Finally, the synthesis of a new family of perylene tetracarboxylate (ptc) based soluble complexes is reported. Structural, magnetic and luminescence properties of selected representatives of this new series of soluble ptc derivatives are reported.
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Bhattacharjee, Subham. "Design, Synthesis and Applications of Novel Two-Component Gels and Soft-Nanocomposites". Thesis, 2014. http://etd.iisc.ac.in/handle/2005/2981.

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Bhattacharjee, Subham. "Design, Synthesis and Applications of Novel Two-Component Gels and Soft-Nanocomposites". Thesis, 2014. http://etd.iisc.ernet.in/handle/2005/2981.

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