Log in

Relevant bibliographies by topics / Photophysical Studies - Organic Molecules

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers
Reports

Academic literature on the topic 'Photophysical Studies - Organic Molecules'

Author: Grafiati

Published: 7 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Photophysical Studies - Organic Molecules.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Photophysical Studies - Organic Molecules"

1

Ramamurthy, V., and J. V. Caspar. "Photophysical Studies of Organic Molecules Included Within Zeolites." Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals 211, no. 1 (January 1992): 211–26. http://dx.doi.org/10.1080/10587259208025822.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Ramamurthy, V., D. F. Eaton, and J. V. Caspar. "Photochemical and photophysical studies of organic molecules included within zeolites." Accounts of Chemical Research 25, no. 7 (July 1992): 299–307. http://dx.doi.org/10.1021/ar00019a005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Mohan, Makesh, Srikala Pangannaya, M. N. Satyanarayan, and Darshak R. Trivedi. "Photophysical and electrochemical properties of organic molecules: Solvatochromic effect and DFT studies." Optical Materials 77 (March 2018): 211–20. http://dx.doi.org/10.1016/j.optmat.2018.01.031.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

RAMAMURTHY, V., D. F. EATON, and J. V. CASPAR. "ChemInform Abstract: Photochemical and Photophysical Studies of Organic Molecules Included within Zeolites." ChemInform 23, no. 41 (August 21, 2010): no. http://dx.doi.org/10.1002/chin.199241288.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Kumari, Rekha, Anitha Varghese, Louis George, and Sudhakar Y. N. "Effect of solvent polarity on the photophysical properties of chalcone derivatives." RSC Advances 7, no. 39 (2017): 24204–14. http://dx.doi.org/10.1039/c7ra01705g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Golcs, Ádám, Bálint Árpád Ádám, Viola Horváth, Tünde Tóth, and Péter Huszthy. "Synthesis, Molecular Recognition Study and Liquid Membrane-Based Applications of Highly Lipophilic Enantiopure Acridino-Crown Ethers." Molecules 25, no. 11 (May 31, 2020): 2571. http://dx.doi.org/10.3390/molecules25112571.

Full text

Abstract:

New highly lipophilic enantiopure crown ethers containing a heterocyclic unit have been synthesized. Phase transport, UV-Vis- and fluorescence spectrophotometric investigations as well as electrochemical studies on the complexation of the new macrocycles with several amine and amino acid derivatives were also carried out. Achiral amines were used for studying the structural preference of the new macrocycles. Among the studied structural features of the guest molecules, the intermolecular π-π interaction showed the most significant effect on complexation, which made the aralkylamine-type compounds the most preferable guest molecules. The studied liquid membrane-based applications and photophysical investigations showed appreciable enantiomeric recognition toward some aralkylamine model compounds with homochiral preferences. New crown ether derivatives (R,R)-2 and (S,S)-2 were successfully applied as enantioselective carrier and sensor molecules.

APA, Harvard, Vancouver, ISO, and other styles

7

Jin, Ruifa, Xiaofei Zhang, and Wenmin Xiao. "Theoretical Studies of Photophysical Properties of D−π−A−π−D-Type Diketopyrrolopyrrole-Based Molecules for Organic Light-Emitting Diodes and Organic Solar Cells." Molecules 25, no. 3 (February 4, 2020): 667. http://dx.doi.org/10.3390/molecules25030667.

Full text

Abstract:

A series of D–π–A diketopyrrolopyrrole(DPP)-based small molecules were designed for organic light-emitting diode(OLEDs) and organic solar cell(OSCs) applications. Applying the PBE0/6-31G(d,p) method, the ground state geometry and relevant electronic properties were investigated. The first excited singlet state geometry and the absorption and fluorescent spectra were simulated at the TD-PBE0/6-31G(d,p) level. The calculated results revealed that the photophysical properties were affected through the introduction of different end groups. Furthermore, the electronic transitions corresponding to absorption and emission exhibited an intramolecular charge transfer feature. Our results suggest that the designed molecules acted not only as luminescent for OLEDs, but also as donor materials in OSCs. Moreover, they can also be used as potential electron transfer materials for OLEDs and OSCs.

APA, Harvard, Vancouver, ISO, and other styles

8

Huang, Ping, Xingzi Zou, Zhiyun Xu, Yanting Lan, Lijuan Chen, Baohua Zhang, and Li Niu. "Studies on Annihilation and Coreactant Electrochemiluminescence of Thermally Activated Delayed Fluorescent Molecules in Organic Medium." Molecules 27, no. 21 (November 2, 2022): 7457. http://dx.doi.org/10.3390/molecules27217457.

Full text

Abstract:

Very recently, there is a great research interest in electrochemiluminescence (ECL) featuring thermally activated delayed fluorescence (TADF) properties, i.e., TADF-ECL. It is appealing since the earlier reports in this topic well-confirmed that this strategy has a great potential in achieving all-exciton-harvesting ECL efficiency under electrochemical excitation, which is a breakthrough in the topic of organic ECL. However, organic phase electrochemistry and ECL studies surrounding TADF-ECL are still extremely rare. Especially, the ECL spectra of previous reported TADF emitters are still very different from their PL spectra. In this work, we systematically measure and discuss the liquid electrochemistry and ECL behavior of two typical TADF molecules in organic medium. Most importantly, we verify for the first time that the ECL spectra of them (coreactant ECL mode) are identical to their PL spectra counterparts, which confirms the effectiveness of TADF photophysical properties in the coreactant ECL mode in practice.

APA, Harvard, Vancouver, ISO, and other styles

9

Uznanski, P., J. Pecherz, and M. Kryszewski. "Photophysical studies of hydrophobically functionalized polyionene systems in aqueous solutions." Canadian Journal of Chemistry 73, no. 11 (November 1, 1995): 2041–46. http://dx.doi.org/10.1139/v95-252.

Full text

Abstract:

Complexes of polyionene and anionic dyes and surfactant were prepared by exchange reaction of counterions in the parent polymer. Fluorescence studies were conducted to observe some characteristic behaviour of these complexes in water Polyionenes with aromatic hydrocarbons adopt an open conformation and there is no evidence for interpolymer interactions. On the contrary, polyionenes with long aliphatic counterions easily form microdomains in aqueous solution due to hydrophobic interaction as evidenced by an increase in excimer emission. Microdomains have an interpolymer nature, as confirmed by measurements of energy transfer from naphthalene to pyrene moieties. Polyionenes with SDS counterions interact with external surfactant molecules and form polymer–surfactant aggregates. Electrostatic repulsions between aggregates dominate on hydrophobic interaction between polymer chains and are responsible for conformational changes. Keywords: hydrophobically modified polymers, surfactants, complexation, fluorescence, nonradiative energy transfer

APA, Harvard, Vancouver, ISO, and other styles

10

Lee, Sanghyuck, Chul Soon Park, and Hyeonseok Yoon. "Nanoparticulate Photoluminescent Probes for Bioimaging: Small Molecules and Polymers." International Journal of Molecular Sciences 23, no. 9 (April 29, 2022): 4949. http://dx.doi.org/10.3390/ijms23094949.

Full text

Abstract:

Recent interest in research on photoluminescent molecules due to their unique properties has played an important role in advancing the bioimaging field. In particular, small molecules and organic dots as probes have great potential for the achievement of bioimaging because of their desirable properties. In this review, we provide an introduction of probes consisting of fluorescent small molecules and polymers that emit light across the ultraviolet and near-infrared wavelength ranges, along with a brief summary of the most recent techniques for bioimaging. Since photoluminescence probes emitting light in different ranges have different goals and targets, their respective strategies also differ. Diverse and novel strategies using photoluminescence probes against targets have gradually been introduced in the related literature. Among recent papers (published within the last 5 years) on the topic, we here concentrate on the photophysical properties and strategies for the design of molecular probes, with key examples of in vivo photoluminescence research for practical applications. More in-depth studies on these probes will provide key insights into how to control the molecular structure and size/shape of organic probes for expanded bioimaging research and applications.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Photophysical Studies - Organic Molecules"

1

Chin, Khin Kein. "Photophysical studies of fullerene derivatives and organic molecular nanocrystals ; and Singlet oxygen in microheterogeneous media: direct characterization in zeolites, proteins, and immunoglobulins." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1779690191&sid=7&Fmt=2&clientId=1564&RQT=309&VName=PQD.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Rubio, Pons Oscar. "Photophysical Properties of Organic and Organometallic molecules." Licentiate thesis, KTH, Biotechnology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1739.

Full text

Abstract:

Highly correlated quantum chemical methods have been appliedto study the photophysical properties of substituted benzenes.With the inclusion of spin-orbit coupling, the phosphorescencesof these molecules have been calculated usingMulti-CongurationalSelf- Consistent Field (MCSCF) quadraticresponse theory. The Herzberg-Teller approximation has beenadopted to evaluate the vibronic contributions tophosphorescence.

The performance of hybrid density functional theory (DFT) atthe B3LYP level is examined in comparison to the MP2, CCSD andCCSD(T) methods for the geometry and permanent dipole moment ofp-aminobenzoic acid. The time-dependent DFT/B3LYP method isapplied to calculate the two-photon absorption of a series ofZinc-porphyrin derivatives in combination with a two-statemodel. The transitions between excited singlet and tripletstates of Zinc and Platinum based organometallic compounds havebeen computed using DFT quadratic response theory. The resultsare used to simulate the non-linear propagation of laser pulsesthrough these materials utilizing a dynamical wave propagationmethod.

APA, Harvard, Vancouver, ISO, and other styles

3

Jones, Derek R. "Design, Synthesis, and Photophysical Properties of Corannulene-based Organic Molecules." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1323350004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Law, Ga-lai. "Synthesis and photophysical studies of organic lanthanide complexes." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38308216.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Law, Ga-lai, and 羅嘉麗. "Synthesis and photophysical studies of organic lanthanide complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38308216.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Rogge, Carsten. "Photophysical studies of organic dyes in polymer matrices." Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266485.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Wong, Ka-Leung. "Synthesis, characterization, and photophysical studies of organic-lanthanide complexes." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36875351.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Wong, Ka-Leung, and 黃嘉良. "Synthesis, characterization, and photophysical studies of organic-lanthanide complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36875351.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Chretien, Michelle N. "Photochemical, photophysical, and photobiological studies of zeolite guest-host complexes." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/29205.

Full text

Abstract:

This thesis focuses on the photochemistry and photophysics of a variety of zeolite complexes, from catalysts to sunscreens. The first chapter describes the preparation and photophysical and photochemical characterization of two new photocatalytic materials. The catalysts are based on a multi-component zeolite, host-guest complex and the interaction between components was probed using time-resolved spectroscopic techniques. The catalytic efficiency, in terms of the ability to photodegrade biological contaminants, was also investigated. These studies were performed with the aim of developing efficient catalysts for wastewater remediation which can be used with solar (visible) radiation. In subsequent chapters, zeolite materials have been used as matrices for the stabilization of various transient or reactive species. In the case of ZSM-5-type zeolite, the dibenzotropylium cation was rendered indefinitely persistent allowing the examination of its excited-state behaviour. The geometric restriction within the cavities also permits the observation of electron transfer chemistry in the absence of a nucleophilic addition reaction with the electron donor. In a second example, ketoprofen (a non-steroidal anti-inflammatory drug) was found to undergo intrazeolite photodecarboxylation to generate a benzylic carbanion. The lifetime of the zeolite-encapsulated carbanion was found to be fifty times longer than in solution. The enhanced lifetime allows intermolecular nucleophilic addition chemistry to compete with protonation, effectively, a photo-initiated Grignard-type reaction is observed. In Chapter 6, fluorescence is used as tool to probe both intra- and interzeolite interactions. In the first part, a zeolite-entrapped radical probe was prepared by ship-in-a-bottle synthesis for the investigation of radical percolation in the zeolite matrix. The probe is a molecular dyad containing a persistent free-radical and a quenched fluorophore. When the probe radical couples with a carbon-centered radical, the probe fluorescence is restored and in this way free-radical species in heterogeneous systems can be conveniently examined. In the second section, zeolite particles were irreversibly labeled with a biologically-compatible fluorophore (also by ship-in-a-bottle synthesis). The last part of this thesis deals with a project relating to supramolecular sunscreens. (Abstract shortened by UMI.)

APA, Harvard, Vancouver, ISO, and other styles

10

Phillips, Tim. "DNA Binding and Photophysical Studies on Organic Derivatives of Dipyridophenazine." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489744.

Full text

APA, Harvard, Vancouver, ISO, and other styles

More sources

Books on the topic "Photophysical Studies - Organic Molecules"

1

F, Liebman Joel, and Greenberg Arthur, eds. Studies of organic molecules. Deerfield Beach, Fla: VCH Publishers, 1986.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

Williams, Craig Denver. Uptake and release studies of simple organic molecules in synthetic zeolites. Salford: University of Salford, 1985.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

Eberhardt, Wolfgang. Applications of Synchrotron Radiation: High-Resolution Studies of Molecules and Molecular Adsorbates on Surfaces. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

4

Cohen, D. M. Two-photon absorption studies in organic molecules. 1994.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

5

Durr, Heinz, and Henri Bouas-Laurent. Photochromism: Molecules and Systems (Studies in Organic Chemistry). Elsevier Publishing Company, 1990.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

6

Launay, Jean-Pierre, and Michel Verdaguer. Electrons in Molecules. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198814597.001.0001.

Full text

Abstract:

The book treats in a unified way electronic properties of molecules (magnetic, electrical, photophysical), culminating with the mastering of electrons, i.e. molecular electronics and spintronics and molecular machines. Chapter 1 recalls basic concepts. Chapter 2 describes the magnetic properties due to localized electrons. This includes phenomena such as spin cross-over, exchange interaction from dihydrogen to extended molecular magnetic systems, and magnetic anisotropy with single-molecule magnets. Chapter 3 is devoted to the electrical properties due to moving electrons. One considers first electron transfer in discrete molecular systems, in particular in mixed valence compounds. Then, extended molecular solids, in particular molecular conductors, are described by band theory. Special attention is paid to structural distortions (Peierls instability) and interelectronic repulsions in narrow-band systems. Chapter 4 treats photophysical properties, mainly electron transfer in the excited state and its applications to photodiodes, organic light emitting diodes, photovoltaic cells and water photolysis. Energy transfer is also treated. Photomagnetism (how a photonic excitation modifies magnetic properties) is introduced. Finally, Chapter 5 combines the previous knowledge for three advanced subjects: first molecular electronics in its hybrid form (molecules connected to electrodes acting as wires, diodes, memory elements, field-effect transistors) or in the quantum computation approach. Then, molecular spintronics, using, besides the charge, the spin of the electron. Finally the theme of molecular machines is presented, with the problem of the directionality control of their motion.

APA, Harvard, Vancouver, ISO, and other styles

7

Fahlman, Mats. Experimental and Theoretical Studies of Organic Molecules for Electronic Devices. Linkoping, 1995.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

8

From Atoms to Molecules: Studies in the History of Chemistry from the 19th Century. Taylor & Francis Group, 2010.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

9

Liebman, Joel F., and Arthur Greenberg. Molecular Structure and Energetics, Studies of Organic Molecules (Molecular Structure and Energetics, Vol 3). Wiley-VCH, 1986.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

10

Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.001.0001.

Full text

Abstract:

Nuclear magnetic resonance spectroscopy (NMR spectroscopy) is a research technique that uses the magnetic properties of atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained. Proton NMR (1H NMR) is a technique that applies NMR spectroscopy specifically to the hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of that substance's molecules. The use of 1H NMR for the assignment of absolute configuration of organic compounds is a well-established technique. Recent research describes the technique's application to mono-, bi- and trifunctional compounds. In addition, several new auxiliary reagents, mono- and biderivatization procedures, on-resin methodologies and more recently, the use of 13C NMR, have been introduced to the field. In The Assignment of the Absolute Configuration by NMR Using Chiral Derivatizing Agents: A Practical Guide, eminent Professor of Organic Chemistry Ricardo Riguera organizes this cutting-edge NMR research. Professor Riguera offers a short and usable guide that introduces the reader to the research with a plethora of details and examples. The book briefly explains the theoretical aspects necessary for understanding the methodology, dedicating most of its space to covering the practical aspects of the assignment, with examples and spectra taken from the authors' own experiments. Upper-level undergraduates, graduate students, and chemical researchers will find this guide useful for their studies and practice.

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Photophysical Studies - Organic Molecules"

1

Miskovsky, P., F. Sureau, L. Chinsky, G. V. Wheeler, and P. Y. Turpin. "Studies of the Photophysical Mechanisms Involved in the Antiviral Activity of Hypericins at the Cellular Level." In Spectroscopy of Biological Molecules, 539–40. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0371-8_248.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Derhaeg, L., C. Samyn, and A. Persoons. "EFISH-Studies of Stilbene- and Thiophene-Derivatives." In Organic Molecules for Nonlinear Optics and Photonics, 177–83. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3370-8_12.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Rusin, Oleksandr, Jorge O. Escobedo, and Robert M. Strongin. "Chemosensors: Case Studies of Indicators for Organic Molecules." In Chemosensors, 429–53. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118019580.ch20.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Roos, Björn O., Markus Fülscher, Per-Åke Malmqvist, Manuela Merchán, and Luis Serrano-Andrés. "Theoretical Studies of the Electronic Spectra of Organic Molecules." In Quantum Mechanical Electronic Structure Calculations with Chemical Accuracy, 357–438. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0193-6_8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Davey, A. P., D. J. Cardin, H. J. Byrne, and W. Blau. "Nonlinear Optical Studies of Transition Metal Containing Conjugated Organic Monomeric and Polymeric Systems." In Organic Molecules for Nonlinear Optics and Photonics, 391–402. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3370-8_29.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Friberg, P., W. M. Irvine, S. C. Madden, and A. Hjalmarson. "Studies of Organic Molecules Containing Methyl Groups in Dark Clouds." In Astrochemistry, 201–2. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-4774-0_34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Saranya, C., and k. Senthilkumar. "Theoretical studies on adsorption of organic molecules on metal surface." In Computational Chemistry Methodology in Structural Biology and Materials Sciences, 209–41. Toronto; New Jersey: Apple Academic Press, 2017.: Apple Academic Press, 2017. http://dx.doi.org/10.1201/9781315207544-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Frauenfelder, H. "Experimental Studies of Protein-Dynamics Through Ligand Binding." In Design and Synthesis of Organic Molecules Based on Molecular Recognition, 143–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70926-5_12.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Scheraga, Harold A. "Theoretical Studies of Molecular Recognition and Catalysis by Enzymes." In Design and Synthesis of Organic Molecules Based on Molecular Recognition, 117–36. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70926-5_10.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Oishi, Tohru. "Structure-Activity Relationship Studies of Maitotoxin Based on Chemical Synthesis." In Cutting-Edge Organic Synthesis and Chemical Biology of Bioactive Molecules, 125–43. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6244-6_6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Photophysical Studies - Organic Molecules"

1

Drake, J. M. "Photophysical Studies of DAQ on Silica and Aluminum Oxides. A Molecular Probe of Surface Heterogeneity." In Microphysics of Surfaces, Beams, and Adsorbates. Washington, D.C.: Optica Publishing Group, 1985. http://dx.doi.org/10.1364/msba.1985.mc5.

Full text

Abstract:

The optical features of organic molecules adsorbed to the surface of oxides, such as silica and alumina, can be strongly perturbed by the chemical properties of the surface adsorption sites. The topography of the surface as it relates to the fractal dimension and its relation to the nature and distribution of surface sites is important information if we are to be able to understand the photophysics and photochemistry of surface bound molecules. The work we report here is for the molecule 1,4 dihydroxyanthraquinone (DAQ, Quinizarin). This molecule provides striking evidence of how the surface of silica gel modifies the optical features of DAQ in different ways depending on the nature of the surface adsorption site.

APA, Harvard, Vancouver, ISO, and other styles

2

Schwartz, Benjamin J., Fumitomo Hide, Mats R. Andersson, and Alan J. Heeger. "Ultrafast Photophysics of Conjugated Polymers, Blends, and Devices." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/up.1996.fe.30.

Full text

Abstract:

The photophysics of conducting polymers are of interest both for the fundamental information they provide about the nature of excitations in low-dimensional systems, and for the enormous practical potential they offer in the production of low cost, readily processible electroluminescent devices.[1-5] The technological goals in constructing organic LED's include improvement of the quantum efficiency of the luminescence and control over the emission frequency. By constructing new polymers with different side groups and doping polymer films with other luminescent molecules, both of these goals can be met. In this paper, we present ultrafast photophysical studies of a novel conjugated polymer with a high luminescence efficiency. Comparison of the transient absorption and emission dynamics of the new polymer, an alkyl-substituted poly(p-phenylenevinylene) (a-PPV), to unsubstituted or alkoxy-substituted PPV's [1-4] demonstrates that non-radiative pathways which compete with luminescent channels are significantly curtailed in the new material. Additional femtosecond studies on a-PPV/dye molecule blends show that rapid energy transfer takes place, opening the possibility for tuning the emission by the choice of dye molecule. Light emitting diodes constructed from the new polymer and the polymer/dye blends demonstrate improvement of the electroluminescence efficiency upon doping, verifying that energy transfer competes effectively with non-radiative channels under in-situ conditions.

APA, Harvard, Vancouver, ISO, and other styles

3

Eich, Manfred, Martin Sprave, Heike Mauermann, Stefan Stein, Klaus Müllen, Werner Frank, and Theo Tschudi. "Studies on Novel Photoselectable Organic NLO-Molecules." In Nonlinear Optics. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/nlo.1992.fa2.

Full text

Abstract:

NLO-chromophores of the azobenzene type and of the stilbene type have been used either as dopants or as sidegroups in polymers in order to realize NLO-materials in which the refractive index and the nonlinear susceptibility could be modified optically.1,2 These changes are based on the photochemical transformation of these molecular units from the elongated trans state to the bent cis-state. Since the trans state is the thermodynamically stable state, the cis-isomers generally undergo a thermally activated relaxation back to trans even below the glass transition temperature.3

APA, Harvard, Vancouver, ISO, and other styles

4

Assis, Francisco F. de, Juliana M. de Souza, Beatriz H. K. Assis, Timothy J. Brocksom, and Kleber T. de Oliveira. "Synthesis and photophysical studies of a chlorin sterically designed to prevent self-aggregation." In 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-bmos2013_2013913102810.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Gonçalves, M. Sameiro, B. Rama Raju, Diogo Sampaio, and Paulo Coutinho. "Ultrasonic Mediated Synthesis of New Benzo[a]phenoxazinium Chlorides and Their Photophysical Studies." In The 16th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2012. http://dx.doi.org/10.3390/ecsoc-16-01112.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Brechignac, Philippe, and Patrice Hermine. "Photophysical studies of jet-cooled PAHs: Emission spectra, lifetimes and van der Waals clusters astrophysical implications." In The 50th international meeting of physical chemistry: Molecules and grains in space. AIP, 1994. http://dx.doi.org/10.1063/1.46586.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Katturi, Naga Krishnakanth, Venkata Suman Krishna Jonnadula, Chinmoy Biswas, Sai Santosh Kumar Raavi, Lingamallu Giribabu, and Venugopal Rao Soma. "Ultrafast photophysical studies and femtosecond third-order nonlinear optical properties of a Soret-band excited zinc phthalocyanine." In Organic Electronics and Photonics: Fundamentals and Devices II, edited by Sebastian Reineke, Koen Vandewal, and Wouter Maes. SPIE, 2020. http://dx.doi.org/10.1117/12.2558067.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Perona, Almudena, Dionisia Sanza, Rosa Claramunta, and José Elguero. "Syntheses and Structural Studies of New Molecules Involving Hydrogen Bonds." In The 9th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2005. http://dx.doi.org/10.3390/ecsoc-9-01472.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Mysliwiec, Jaroslaw, Adam Szukalski, Lech Sznitko, Andrzej Miniewicz, and Karolina Haupa. "Studies of new organic molecules and hybrid systems for lasing applications." In SPIE OPTO, edited by Christopher E. Tabor, François Kajzar, Toshikuni Kaino, and Yasuhiro Koike. SPIE, 2013. http://dx.doi.org/10.1117/12.2008304.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Gonçalves, M. Sameiro, Paulo Coutinho, and Sarala Naik. "N-Alkyl-N-[5-(propylamino)-9H-benzo[a]phenoxazin-9-ylidene]alkan-1- aminium chlorides: synthesis and photophysical studies." In The 13th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2009. http://dx.doi.org/10.3390/ecsoc-13-00184.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Photophysical Studies - Organic Molecules"

1

López-Valverde, Nansi, Javier Aragoneses, Antonio López-Valverde, Cinthia Rodríguez, and Juan Manuel Aragoneses. Role in the osseointegration of titanium dental implants, of bioactive surfaces based on biomolecules: A systematic review and meta-analysis of in vivo studies. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, June 2022. http://dx.doi.org/10.37766/inplasy2022.6.0076.

Full text

Abstract:

Review question / Objective: Does the bioactive surface of titanium dental implants, based on biomolecules, influence osseointegration?. The aim of our study was to evaluate the role and efficacy of bioactive surfaces in osseointegration. Our review study limited the research interest to titanium dental implants coated with a biomolecule, i.e., an organic molecule produced by a living organism. Condition being studied: In recent years, much attention has been paid to topographical modifications of dental implant surfaces, as well as to their coating with biologically active substances.a bioactive surface is one capable of achieving faster and higher quality osseointegration, shortening waiting times and solving situations of poor bone quality. Molecules that can be applied for bioactive purposes include bioceramics, ions and biomolecules. Collagen and bone morphogenetic protein have been suggested as bone stimulating agents. Biofunctionalization of the implant surface with a biomimetic active peptide has also been shown to result in a significant increase in bone-to-implant ratios and an increase in peri-implant bone density.

APA, Harvard, Vancouver, ISO, and other styles

2

Phillips, Donald A., Yitzhak Spiegel, and Howard Ferris. Optimizing nematode management by defining natural chemical bases of behavior. United States Department of Agriculture, November 2006. http://dx.doi.org/10.32747/2006.7587234.bard.

Full text

Abstract:

This project was based on the hypothesis that nematodes interacting with plants as either parasites or beneficial saprophytes are attracted to their host by natural products. This concept was supported by numerous observations that parasitic nematodes are attracted to root exudates. Our overall goal was to identify nematode sensory compounds from root exudates and to use that information for reducing nematicide applications. We applied skills of the investigators to achieve three specific objectives: 1) Identify nematode behavioral cues (e.g., attractants or repellents) in root exudates; 2) Identify new natural nematicidal compounds; and 3) Combine a natural attractant and a nematicide into a nematode trap. Because saprophytic nematodes benefit plants by mineralizing organic matter, we sought compounds attractive primarily to parasitic nematodes. The project was constructed on several complementary foundations. First, data from Dr. Spiegel’s lab showed that under aseptic conditions Ditylenchus dipsaci, a parasite on onion, is attracted to certain fractions of onion root exudates. Second, PI Phillips had a sizeable collection of natural plant products he had identified from previous work on Rhizobium-legume interactions, which could be tested “off the shelf”. Third, Dr. Ferris had access to aseptic and natural populations of various saprophytic and parasitic nematodes. The project focused on five nematode species: D.dipsaci, Heterodera avenae, and Tylenchulussemipenetransat ARO, and Meloidogyne javanicand Caenorhabditis elegans at UCD. Ten pure plant compounds, mostly flavonoids, were tested on the various nematode species using six different assay systems. Results obtained with assorted test systems and by various scientists in the same test systems were essentially irreproducible. Many convincing, Many convincing, i.e. statistically significant, results in one system or with one investigator could not be repeated with other assays or different people. A recent report from others found that these compounds, plus another 30, were inactive as attractants in three additional parasitic nematode species (Wuyts et al. Nematology 8:89- 101, 2006). Assays designed to test the hypothesis that several compounds together are required to attract nematodes have thus far failed to find a reproducibly active combination. In contrast to results using pure plant compounds, complex unfractionated exudates from aseptic onion root reproducibly attracted D. dipsaci in both the ARO and UCD labs. Onion root exudate collection, separation into HPLC fractions, assays using D. dipsaci and MS-MS experiments proceeded collaboratively between ARO and UCD without any definitive identification of an active compound. The final active fraction contained two major molecules and traces of several other compounds. In the end, analytical studies were limited by the amount of onion root exudate and the complexity of the purification process. These tests showed that aseptic plant roots release attractant molecules, but whether nematodes influence that release, as insects trigger release of attractants from plants, is unknown. Related experiments showed that the saprophyte C. elegans stimulates its prey, Pseudomonas bacteria, to increase production of 2, 4-diacetylphloroglucinol (DAPG) a compound that promotes amino acid exudation by plant roots. It is thus possible that saprophytic nematodes are attracted primarily to their bacterial or fungal prey and secondarily to effects of those microorganisms on root exudation. These observations offer promising avenues for understanding root-zone interactions, but no direct routes to controlling nematodes in agriculture were evident. Extracts from two plant sources, Chrysanthemum coronarium and Sequoia sempervirens, showed nematicidal activity at ARO and UCD, respectively. Attempts to purify an active compound from S. sempervirens failed, but preliminary results from C. coronarium are judged to form a potential basis for further work at ARO. These results highlight the problems of studying complex movement patterns in sentient organisms like nematodes and the issues associated with natural product isolation from complex mixtures. Those two difficulties combined with complications now associated with obtaining US visas, slowed and ultimately limited progress on this project. As a result, US investigators expended only 65% of the $207,400 originally planned for this project. The Israeli side of the project advanced more directly toward its scientific goals and lists its expenditures in the customary financial report.

APA, Harvard, Vancouver, ISO, and other styles

3

Gerstl, Zev, Thomas L. Potter, David Bosch, Timothy Strickland, Clint Truman, Theodore Webster, Shmuel Assouline, Baruch Rubin, Shlomo Nir, and Yael Mishael. Novel Herbicide Formulations for Conservation-Tillage. United States Department of Agriculture, June 2009. http://dx.doi.org/10.32747/2009.7591736.bard.

Full text

Abstract:

The overall objective of this study was to develop, optimize and evaluate novel formulations, which reduce herbicide leaching and enhance agronomic efficacy. Numerous studies have demonstrated that CsT promotes environmental quality and enhances sustainable crop production, yet continued use of CsT-practices appears threatened unless cost effective alternative weed control practices can be found. The problem is pressing in the southern portion of the Atlantic Coastal Plain region of the eastern USA where cotton and peanut are produced extensively. This research addressed needs of the region’s farmers for more effective weed control practices for CsT systems. HUJI: CRFs for sulfentrazone and metolachlor were developed and tested based on their solubilizion in cationic micelles and adsorption of the mixed micelles on montmorillonite. A better understanding of solubilizing anionic and nonionic organic molecules in cationic micelles was reached. Both CRFs demonstrated controlled release compared to the commercial formulations. A bioassay in soil columns determined that the new sulfentrazone and metolachlor CRFs significantly improve weed control and reduced leaching (for the latter) in comparison with the commercial formulations. ARO: Two types of CRFs were developed: polymer-clay beads and powdered formulations. Sand filter experiments were conducted to determine the release of the herbicide from the CRFs. The concentration of metolachlor in the initial fractions of the effluent from the commercial formulation reached rather high values, whereas from the alginate-clay formulations and some of the powdered formulations, metolachlor concentrations were low and fairly constant. The movement of metolachlor through a sandy soil from commercial and alginate-clay formulations showed that the CRFs developed significantly reduced the leaching of metolachlor in comparison to the commercial formulation. Mini-flume and simulated rainfall studies indicated that all the CRFs tested increased runoff losses and decreased the amount of metolachlor found in the leachate. ARS: Field and laboratory investigations were conducted on the environmental fate and weed control efficacy of a commercially available, and two CRFs (organo-clay and alginate-encapsulated) of the soil-residual herbicide metolachlor. The environmental fate characteristics and weed control efficacy of these products were compared in rainfall simulations, soil dissipations, greenhouse efficacy trials, and a leaching study. Comparisons were made on the basis of tillage, CsT, and conventional, i.e no surface crop residue at planting (CT). Strip-tillage (ST), a commonly used form of CsT, was practiced. The organo-clay and commercial metolachlor formulations behaved similarly in terms of wash off, runoff, soil dissipation and weed control efficacy. No advantage of the organo-clay over the commercial metolachlor was observed. Alginate encapsulated metolachlor was more promising. The dissipation rate for metolachlor when applied in the alginate formulation was 10 times slower than when the commercial product was used inferring that its use may enhance weed management in cotton and peanut fields in the region. In addition, comparison of alginate and commercial formulations showed that ST can effectively reduce the runoff threat that is commonly associated with granular herbicide application. Studies also showed that use of the alginate CRF has the potential to reduce metolachlor leaching. Overall study findings have indicated that use of granular herbicide formulations may have substantial benefit for ST-system weed management for cotton and peanut production under Atlantic Coastal Plain conditions in the southeastern USA. Commercial development and evaluation at the farm scale appears warranted. Products will likely enhance and maintain CsT use in this and other regions by improving weed control options.

APA, Harvard, Vancouver, ISO, and other styles

4

Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen, and Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils: Speciation, Transport, and Accumulation. United States Department of Agriculture, June 2011. http://dx.doi.org/10.32747/2011.7697103.bard.

Full text

Abstract:

Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!