Excited State Absorption
Mostrando 1-12 de 99 artigos, teses e dissertações.
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1. JUDD-OFELT ANALYSIS OF Tb3+ AND UPCONVERSION STUDY IN Yb3+-Tb3+ CO-DOPED CALIBO GLASSES
We report on the study of the spectroscopic properties in Ytterbium-Terbium (Yb3+-Tb3+) co-doped calcium lithium borate (CaLiBO) glasses, with the study’s focus being on the upconversion process. Intensity parameters Ωλ for CaLiBO:Tb3+ are determined by the Judd-Ofelt method to be Ω2 = 15.5 × 10-20 cm2, Ω4 = 1.90 × 10-20 cm2 and Ω6 = 3.69 × 10-20 c
Quím. Nova. Publicado em: 2020-02
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2. Water-Soluble Benzazole Dyes Fluorescent by ESIPT: Structural Characterization, Photophysical Properties and Its Application as a Probe for Direct Staining of Helminths
A series of four water-soluble benzazole dyes that emit fluorescence by the excited state intramolecular proton transfer (ESIPT) mechanism were structurally characterized by Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) attached proton test (APT) and mass spectrometry. Their photophysical properties were systemat
J. Braz. Chem. Soc.. Publicado em: 2019-03
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3. Synthesis, Photophysical and Electrochemical Properties of Novel D-π-D and D-π-A Triphenylamino-Chalcones and β-Arylchalcones
A series of triphenylamino (TPA)-chalcones and triphenylamino-β-arylchalcones, displaying either D-π-D or D-π-A architecture, were synthesized through aldol condensations and Heck reactions. The chalcone derivatives display intense absorption bands ranging from 389 to 432 nm and molar extinction coefficients of ca. 105 L mol-1 cm-1 corresponding to π-π*
J. Braz. Chem. Soc.. Publicado em: 2019-01
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4. On the Fluorescent, Steric and Electronic Factors Affecting the Detection of Metallic Ions Using an Imidazolyl-Phenolic Derived Fluorescent Probe
The imidazolyl-phenolic probe used at the present study has its photophysic properties regulated by a tautomeric equilibrium. After the absorption of a photon, an excited state intramolecular proton transfer process generates a ketonic species, responsible for the 440 nm emission (in CH3CN/H2O, 95:5, v/v). Addition of Cu2+, Al3+, Cr3+ and Fe3+ suppresses emi
J. Braz. Chem. Soc.. Publicado em: 2017-10
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5. Synthesis and Photophysical Characterization of Proton Transfer-Based Thiourea Derivatives: Potential Application as Colorimetric Naked-Eye Chemosensor for Fluoride Detection in Solution
Two new thiourea derivatives were synthesized through the reaction of photoactive aminohydroxybenzazoles and p-isothiocyanate benzoic acid via nucleophilic addition reaction. The compounds were characterized using high resolution mass spectrometry with eletrospray ionization (HRMS-ESI), Fourier transform infrared (FTIR), 13C and 1H nuclear magnetic resonance
J. Braz. Chem. Soc.. Publicado em: 2017-09
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6. A importância do estado excitado 3MLCT de compostos de Ru(II), Re(I) e Ir(III) no desenvolvimento de fotossensores, oleds e fotorredução de CO2
The photochemistry and photophysics of coordination compounds have been extensively investigated not only because their structure, stability, reactivity dependence on the metal center oxidation state and the coordinated ligand; but also for their electronic transitions in a wide range of visible radiation. The knowledge of light absorption, excited state dea
Quím. Nova. Publicado em: 2017-02
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7. DISEÑO Y CARACTERIZACIÓN TEÓRICA DE MATERIALES FOTOACTIVOS EFICIENTES BASADOS EN DERIVADOS DE NAFTOPIRROL Y DE NAFTOTIOFENO PARA CELDAS SOLARES ORGÁNICAS
In this research we have designed electron donors D-π-A type containing two different π fragments to obtain naphthopyrrole (D-NPR-A) and naphthotiophene (D-NTP-A) derivatives, proposed for the use in organic bulk hetero-junction (BHJ) solar cells (OSCs). These derivatives were characterized by DFT and TD-DFT calculations. For all the electron donors the an
Quím. Nova. Publicado em: 2016-08
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8. First Principles Study on the Electronic Structure and Optical Property of Nd-C Codoped Anatase TiO 2
ABSTRACT Band structures, density of states, and absorption spectra of pure, Nd doped, C doped, and Nd-C codoped TiO2 are calculated using first-principles based on density functional theory. Calculation results show that Nd 4f state forms empty impurity energy levels below conduction band, and C 2p state together with Nd 2f state forms occupied impurity ene
Matéria (Rio J.). Publicado em: 2016-06
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9. Synthesis and Photophysical Characterization of Novel ESIPT Triazinyl-Benzazole Derivatives
In this work, the synthesis, characterization and photophysical study of new derivatives of triazinyl-benzazoles with fluorescence by excited-state intramolecular proton transfer (ESIPT) are presented. It regards the synthesis of cyanuric chloride with different 2-(2’-hydroxyphenyl) benzazoles, two quite attractive groups from the synthetic and technologic
J. Braz. Chem. Soc.. Publicado em: 2015-12
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10. Effects of Methyl-Substituted Phenanthrolines on the Performance of Ruthenium(II) Dye-Sensitizers
Tris-heteroleptic ruthenium(II) cis-[Ru(Me4-phen)(dcbH2)(NCS)2], where Me4-phen = 3,4,7,8-tetramethyl-1,10-phenanthroline, dcbH2 = 4,4'-dicarboxylic acid 2,2'-bipyridine, was synthesized, purified and characterized. Its characteristics were compared with those determined for cis-[Ru(Me2-phen)(dcbH2)(NCS)2] and cis-[Ru(phen)(dcbH2)(NCS)2] aiming to evaluate t
J. Braz. Chem. Soc.. Publicado em: 2015-11
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11. Quinolines by Three-Component Reaction: Synthesis and Photophysical Studies
The synthesis of five quinolines 8-octyloxy-4-[4-(octyloxy)phenyl]quinoline and 6-alkoxy- 2-(4-alkoxyphenyl)-4-[(4-octyloxy)aryl]quinolines are described by three-component coupling reaction mediated by Lewis acid FeCl3 and Yb(OTf)3. 4-n-octyloxybenzaldehyde, anisaldehyde, 4-n-octyloxyaniline p-anisidine, and 1-ethynyl-4-heptyloxybenzene, 1-ethynyl-4-octylox
J. Braz. Chem. Soc.. Publicado em: 2015-03
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12. Simulação da dinâmica do estado excitado em semicondutores orgânicos / Simulation of the excited state dynamics in organic semiconductors
In the present work, the Monte Carlo method and the direct numerical integration of the Master Equation were employed to simulate the excitation spectral diffusion process in light emitting polymeric systems. The methodology employed a competition among the internal intra-molecular relaxation, the inter-molecular incoherent energy transfer via Förster mecha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2012