Tesis sobre el tema "Flavonoïdes – Dérivés – Propriétés optiques"
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Labarrière, Luc. "Spectroscopic properties of environmental relevant systems : 2’,3-dihydroxyflavone-ion complexes and polycyclic aromatic hydrocarbons : a joint experimental and theoretical study". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR069.
This manuscript reports the results of an experimental and theoretical study of two molecular systems of environmental interest: 2',3-dihydroxyflavone (2'3HF) and polycyclic aromatic hydrocarbons (PAH). These systems were studied by a combination of electronic spectroscopic techniques (absorption and fluorescence) and quantum chemical calculations (DFT and TD-DFT). In the first part of this thesis, it is shown that 2'3HF has singular acid-base properties compared to other flavonols. The decrease of the pKa by several units is attributed to the presence of a hydrogen-bond network. In the excited state, an intramolecular proton transfer causes a dual fluorescence. An additional emission band, seemingly originating from a tautomeric form perturbed by interaction with the solvent, was revealed. Finally, an exhaustive study of the Ca(II), Mn(II) and Zn(II) complexes showed the formation of chelates with the α-hydroxyketone function. In the second part, three structural hypotheses to explain the experimental observation of visible-range laser-induced fluorescence (LIF) were explored. A study of van der Waals (vdW) dimers of PAHs provided insights into the nature of the monomer interaction and highlighted the difficulty of modelling these systems. However, the calculated electronic transitions suggest that these species cannot be responsible for the LIF signals. Secondly, an identical study of aliphatically bridged PAHs showed very similar results to vdW dimers, ruling out their involvement in the observed fluorescence. Finally, the hypothesis of emission from PAH radicals was explored. The latter is very promising and opens the way for further experimental and theoretical studies
Sahraoui, Bouchta. "Propriétés optiques non-linéaires du troisième ordre dans des nouveaux dérivés du tetrathiafulvalène". Angers, 1996. http://www.theses.fr/1996ANGE0010.
Busch, Alexandrine. "Synthèse de dérivés de benzo- et pyridodiazines à propriétés optiques non linéaires potentielles". Rouen, INSA, 2005. http://www.theses.fr/2005ISAM0004.
Hergué, Noémie. "Nouveaux polymères conjugués dérivés de 4-cyano-3alcoxythiophènes et de dialcoxythiénothiophènes". Angers, 2007. http://www.theses.fr/2007ANGE0049.
This work deals with the synthesis of new polymers using alkoxythiophene derivatives. After a rapid review on the linear conjugated systems properties, a first part is devoted to the presentation of several polyalkoxythiophenes reported in literature. The electronic and structuring effects of the alkoxy groups on the properties og conjugated systems are demonstrated. The second part describes the synthesis of new donner/acceptor systems and the preparation of the resulting polymers. The introduction of electron releasing (alkoxy) and the electron withdrawing (nitrile) groups on the same thiophene ring is used to increase the electronic density homogeneity and to prepare low bandgap polymers. The last part is devoted to the synthesis of 3,6-dialkoxythiéno[3,2-b]thiophene and de 3,4-dialkoxythiéno[3,2-b]thiophene, wich associate the intrinsically rigid structure of thienothiophenes and the autorigidification due to the presence of alkoxy groups. The two structure leads to systems presenting very different properties, thus allowing the modulation of the electronic properties of the various conjugatede systems
Besson, Eric. "Elaboration de matériaux hybrides organiques-inorganiques à propriétés optiques". Montpellier 2, 2004. http://www.theses.fr/2004MON20104.
Drolet, Nicolas. "Étude de dispositifs électro-optiques à base de matériaux dérivés de l'unité 2,7-carbazole". Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23878/23878.pdf.
Wakim, Salem. "Elaboration de structures conjuguées chirales à partir de dérivés du trans (1R, 2R)-1,2-diaminocyclohexane. Evaluation des propriétés catalytiques et optiques". Montpellier 2, 2002. http://www.theses.fr/2002MON20018.
Tokumoto, Miriam Sanae. "Etude struturale des précurseurs, intermédiaires et colloi͏̈des dérivés de l'acétate de zinc et propriétés électriques, optiques et structurales des couches minces d'oxyde de zinc dopé au indium". Limoges, 2000. http://www.theses.fr/2000LIMO0037.
Yang, Zhixin. "Préparation et propriétés des polycarbosilanes comportant des groupements acétyléniques et aromatiques dans le squelette". Montpellier 2, 1992. http://www.theses.fr/1992MON20177.
Eid, Georges. "Nouveaux dérivés lipophiles ou amphiphiles de composés phénoliques bio-sourcés à propriétés antioxydantes, anti-inflammatoires et/ ou anti-prolifératives". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0166.
The decrease in easily accessible petrochemical resources has given over the past ten years a growing interest in the use of raw materials of renewable origin. The primary wood processing industry generates large amounts of waste each year which are currently either recycled to other sectors such as paper mills or the panel industry, or used as a source of energy, and therefore to markets with low added value. The project is situated in this context of sustainable development, circular economy and valorization of co-products of the wood industry by the exploitation of secondary metabolites present in wood, such as phenolic compounds, and more precisely flavonoids, which are indeed of interest in various fields because of their biological activities.The objective of this work is to functionalize accessible and abundant compounds in order to obtain polyfunctional compounds with 2-in-1 properties and thus be able to simplify cosmetic formulations. Functionalization has been considered by two routes: chemical hemisynthesis and/or enzymatic catalysis.By chemical hemisynthesis we were able to obtain bi-modular compounds by combining a fatty acid and a non-glycosylated flavonoid, in this case we worked with catechin. Direct acylations on the phenolic hydroxyls of catechin have been studied and the regioselectivity has been demonstrated by NMR spectroscopy and confirmed by molecular modelling. We have also obtained tri-modular compounds by chemical hemisynthesis by combining different amino acids, as well as fatty acids of variable length with catechin. Three different trimodular structures have been synthesized.By enzymatic hemisynthesis we have synthesized tri-modular compounds, from glycosylated flavonoids, rutin and narignin, aiming for the grafting of fatty acids of different chain lengths but this time on the glycosidic part of the flavonoids. We have also synthesized penta-modular compounds resulting from the grafting of a dicarboxylic acid on naringin or rutin. These compounds comprise two flavonoid entities grafted on either side of the carbon chain of the diacid.At the end of these syntheses, the physico-chemical properties of the products were studied, in particular their solubility in water, their anti-radical properties but also the surfactant properties. Some biological activities have also been studied such as antiproliferative activity against CaCo2 cells. In order to understand the effect of the structure of the compounds on their antioxidant capacity, molecular modeling work has been undertaken; correlations between the antioxidant activity of compounds determined experimentally and chemical reactivity descriptors calculated in silico were sought
Debus, Bruno. "Nanoparticules organiques à base d‟Hexaarylbiimidazoles : caractérisation et propriétés photochromes". Electronic Thesis or Diss., Lille 1, 2013. http://www.theses.fr/2013LIL10128.
This work deals with the study of photochromic organic nanoparticles of bridged-Hexaarylbiimidazoles (HABIs) molecules. Two synthesis paths were proposed. On the one hand, laser photofragmentation (I) for which photochromic reaction and matter fragmentation occur simultaneously. On the other hand, the reprecipitation method (II) does not involve light excitation. The photodynamics of bridged-HABIs has been characterized for the first time using electronic (UV – visible) and vibrational (IR) transient absorption spectroscopy in femtosecond and nanosecond time scale. Transient spectra were analyzed by a chemometric approach based on multivariate curve resolution. The algorithm was adapted to deal with specific signals such as vibrational relaxation processes. For nanoparticles synthesized with (I), we report: i) a photo-dissociation and an increase of the distance between imidazole groups within 210 fs, ii) a partial rotation of the former in 5 ps, iii) a slow relaxation in about 200 ps and iv) a fast thermal back reaction (≈ 800 µs compare to 300 ms in solution). However, for nanoparticles synthesized by (II), the thermal back reaction is similar to the one reported in solution. This suggests that photofragmentation induces a molecular rearrangement with a specific geometry as observed in single crystal. This hypothesis is discussed on the basis of theoretical chemistry calculation and by comparing HABI’s properties in solution and in polycrystalline powder
Asteian, Alice. "Synthèse et applications biologiques de nouveaux dérivés flavonoïques à caractère antioxydant : impact sur le stress oxydant au cours de l'ischémie / reperfusion myocardique chez le rat normal et diabétique". Electronic Thesis or Diss., Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10123.
Flavonoids are natural polyphenolic compounds, and epidemiological and pharmacological studies have shown that flavonoids intake is associated with many beneficial effects. An important example is the 3’,4’-dihydroxyflavonol (DiOHF) which showed interesting therapeutic properties in vitro so it could be considered as an important lead compound to the treatment of cardiovascular diseases. However is poor water solubility prevents it use as a drug. Starting from this model we have synthesized a series of new flavones functionalized by a hydrophilic group in order to increase water solubility. To obtain these derivatives we have set up a fast, simple and clean method without formation of by-products, using micro-waves irradiation to optimize yield and to decrease reaction time. Our second purpose was to investigate the antioxidant activity of the synthesized compounds by undergoing several assays. The most promising compounds were tested in biological studies, in vitro and in vivo. The results showed a significant enhancement of the post-ischemic mechanical function recovery in vivo and in vitro. Another purpose was to designed new flavonols linked to selected antidiabetic moieties already used in the treatment of insulinoresistance. It was shown that these new compounds retain the antioxidant properties of the parent flavonols, and can be of interest in the development of new diabete 2 treatments
Debus, Bruno. "Nanoparticules organiques à base d‟Hexaarylbiimidazoles : caractérisation et propriétés photochromes". Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10128/document.
This work deals with the study of photochromic organic nanoparticles of bridged-Hexaarylbiimidazoles (HABIs) molecules. Two synthesis paths were proposed. On the one hand, laser photofragmentation (I) for which photochromic reaction and matter fragmentation occur simultaneously. On the other hand, the reprecipitation method (II) does not involve light excitation. The photodynamics of bridged-HABIs has been characterized for the first time using electronic (UV – visible) and vibrational (IR) transient absorption spectroscopy in femtosecond and nanosecond time scale. Transient spectra were analyzed by a chemometric approach based on multivariate curve resolution. The algorithm was adapted to deal with specific signals such as vibrational relaxation processes. For nanoparticles synthesized with (I), we report: i) a photo-dissociation and an increase of the distance between imidazole groups within 210 fs, ii) a partial rotation of the former in 5 ps, iii) a slow relaxation in about 200 ps and iv) a fast thermal back reaction (≈ 800 µs compare to 300 ms in solution). However, for nanoparticles synthesized by (II), the thermal back reaction is similar to the one reported in solution. This suggests that photofragmentation induces a molecular rearrangement with a specific geometry as observed in single crystal. This hypothesis is discussed on the basis of theoretical chemistry calculation and by comparing HABI’s properties in solution and in polycrystalline powder
Asteian, Alice. "Synthèse et applications biologiques de nouveaux dérivés flavonoïques à caractère antioxydant : impact sur le stress oxydant au cours de l'ischémie / reperfusion myocardique chez le rat normal et diabétique". Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10123.
Flavonoids are natural polyphenolic compounds, and epidemiological and pharmacological studies have shown that flavonoids intake is associated with many beneficial effects. An important example is the 3’,4’-dihydroxyflavonol (DiOHF) which showed interesting therapeutic properties in vitro so it could be considered as an important lead compound to the treatment of cardiovascular diseases. However is poor water solubility prevents it use as a drug. Starting from this model we have synthesized a series of new flavones functionalized by a hydrophilic group in order to increase water solubility. To obtain these derivatives we have set up a fast, simple and clean method without formation of by-products, using micro-waves irradiation to optimize yield and to decrease reaction time. Our second purpose was to investigate the antioxidant activity of the synthesized compounds by undergoing several assays. The most promising compounds were tested in biological studies, in vitro and in vivo. The results showed a significant enhancement of the post-ischemic mechanical function recovery in vivo and in vitro. Another purpose was to designed new flavonols linked to selected antidiabetic moieties already used in the treatment of insulinoresistance. It was shown that these new compounds retain the antioxidant properties of the parent flavonols, and can be of interest in the development of new diabete 2 treatments
Yang, Sheng-Hsiung. "Synthèse et caractérisation des dérivés de poly(2,3-diphényl-1,4-phénylène vinylène) et des composites poly(1,4-phénylène vinylène) / nanoparticules d'oxyde : propriétés optiques et électrique des diodes utilisant des films composites comme couches actives". Nantes, 2004. http://www.theses.fr/2004NANT2030.
In this thesis, we have studied the new materials for the fabrication of organic electroluminescent devices. In the first part, we have synthesized and characterized the poly(2,3-diphenyl-1,4 phenylene vinylene) or DP-PPV. This polymer contains liquid crystalline groups and can emit polarized light. Then we synthesized and characterized the PPV based composites containing silicon and titanium oxide nanoparticles. These light-emitting materials possess a better stability than the bare polymer because of the presence of the oxide nanoparticles. The modifications of the optical and electrical properties obtained in the materials can be explained by physical processes which highlight the role of the particles inside the polymer structure : reduction of the conjugation length of the chains, formation of the conducting pathways inside the polymer matrix, interaction nanoparticles-polymer, increase of the surface contact polymer-electrode
Diaw, Abdou Karim Diagne. "Electrosynthèse, caractérisation et propriétés optique du Poly-N-phénylpyrrole dans divers milieux et sur divers substrats : étude de l'effet catalytique du pyrrole et de l'effet d'inhibition de corrosion : synthèse organique, électropolymérisation en milieu organique, caractérisation et propriétés optiques des dérivés p-substitués du poly(N-PhPy)". Paris 7, 2010. http://www.theses.fr/2010PA077014.
Two strategies are proposed to improve the organic polymer solubility for their use as active components in electronic devices: in the first one N-phenylpyrrole (N-PhPy) is electropolymerized in micellar solution, which increases solubility of resulting polymers; in the second one an electron-donating substituent is grafted in the para position of phenyl in N-PhPy moiety by chemical synthesis, followed by an electropolymerization process. A direct micellar medium (SDS + water + perchloric acid) and an inverse micellar medium (AOT + alcane (octane) + perchloric acid) are used to electrosynthesize poly(N-PhPy) films on Pt. These films present a good solubility, which also allowed us to characterize their structure by MALDI-TOF mass spectrometry, and to study their optic properties in organic solution. We were able to synthetize with satisfactory yields (36-81 %), by the Clauson-Kaas modified method and the Still method and to characterize a new series of N-PhPy para-substituted derivatives and new symmetrical and asymmetrical mono and oligophenylenethiophene compounds with one (or 2) pyrrole(s) at the chain end (ThPhPy and PyPhThThPhPy). We electrosynthesized in organic medium, very electroactive and adherent poly(MPhPy), poly(HPhPy), poly(ThPhPy), poly(PhDPy) and poly (DPhDPy) films on Pt. FT-IR spectroscopy showed the existence of a coupling in the a - a' positions of pyrrolic rings, having pendant phenyl groups with an electron-donating substituent in para. We compared the optic properties of these N-PhPy derivatives and of corresponding soluble polymers [poly(MPhPy), poly(HPhPy), poly(ThPhPy)] in organic solution and measured the fluorescence quantum yields and decays
Hajlaoui, Riadh. "Effet de la structure sur les propriétés électriques et optiques d'oligomères conjugués semi-conducteurs. Application à la réalisation de transistors à effet de champ et de diode électroluminescentes". Rouen, 1995. http://www.theses.fr/1995ROUES005.
Pathan, Shaheen. "Développement de matériaux flexibles optiquement actifs basés sur des nanostructures hybrides chirales de modèle d’assemblage moléculaire". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0126.
In this work, we focused on the creation of optically active chiral nanostructures by fabricating fluorescent silica nanohelices in order to obtain optically active nanoscale soft materials for applications as nanophotonics materials. For this purpose, silica chiral nanohelices were used for grafting and organizing achiral fluorescent inorganic nanocrystals, dyes, molecules, and fluorescent polymers through different approaches. These inorganic helices were formed via sol-gel method using organic helical self–assemblies of surfactant molecules (achiral and cationic gemini surfactant, with chiral counterion, tartrate) as templates. First, the surface of helical silica was functionalized by APTES in order to graft inorganic quantum dots ZnS-AgInS2 with different capping ligands. In the second part, fluorescent anthracene derivative polymer was organized via deposition and absorption on the surface of helical silica. To investigate the chiroptical properties, circular dichroism and circularly polarised luminescence characterization were performed.In the first chapter, the bibliographic study on different chiral organic self-assembling systems and their chiroptical properties are shown. The studies on the formation of chiral self-assembled systems in different conditions, structural morphology, fabrication techniques and their applications are discussed followed by the use of fluorescent nanocrystals, i.e., quantum dots (QDs) and achiral fluorescent polymers on which chiroptical properties can be obtained and their applications in optical nanodevices, sensors, and nano-photonics.In the first part of the second chapter, different characterisation techniques such as transmission electron microscope (TEM) , high resolution transmission electron microscope (HRTEM), and confocal microscopy, UV-Vis spectroscopy and fluorescence spectroscopies, as well as circular dichroism (CD) and circularly polarised luminescence (CPL) spectroscopies are described. In the second part, the synthesis of Gemini 16-2-16 as well as their self-assemblies mechanism, and their transformation to silica replica via sol-gel chemistry are described. These silica nanohelices are functionalized by 3-aminopropyltriethoxysilane (APTES). Their analysis is performed by Thermogravimetric analysis (TGA) and elementary analysis (EA).In the third Chapter, we focused on the synthesis of inorganic ((ZnS)x-1(AgInS2)x) QDs with different compositions molar ratio and its characterizations by TEM, TGA, EA, Fourier-transform infrared spectroscopy (FTIR), zeta potential measurements, absorption, and emission spectroscopy. Four types of ligands were used to cap the QDs via phase ligand exchange as follows: ammonium sulphide (AS), 3-mercaptopropionic acid (MPA), l-cysteine (L-Cys) and the fourth one is oleylamine (OLA). These QDs are grafted on the surface of amine-modified silica helices through ionic interaction. Various techniques were used to show the grafting of QDs on the surface of silica helix, and their optical properties were studied using absorption and emission spectroscopy. After grafting, in each case of ligands, different results were observed as follows: The TEM characterization shows that QDs are grafted on the surface of silica helices. In the case of AS-capped QDs, the helical morphology of silica helices after grafting is destroyed; therefore the further ananlysis was not possible. While, in the cases of QDs with three other ligands MPA, OLA and L-cys, dense and homogeneous grafting of the QDs were observed by TEM and the helical morphology was preserved after their grafting. The HRTEM images were taken on the MPA-QDs@silica helices and energy-dispersive x-ray (EDX) analysis was performed in STEM mode, confirming the QDs elements present on the silica surfaces. [...]