Electronic Structure and Optical Response of Electroluminescent Conjugated Polymers

1997 ◽  
Vol 488 ◽  
Author(s):  
J. L. Bredas ◽  
J. Cornil ◽  
D. Beljonne ◽  
D. A. Dos Santos ◽  
Z. Shuaiv ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Electronic Structure ◽  
Quantum Yield ◽  
Conjugated Polymers ◽  
Quantum Chemical Calculations ◽  
Theoretical Approach ◽  
Quantum Chemical ◽  
Fluorescence Quantum Yield ◽  
Remarkable Agreement

AbstractIn this contribution, we investigate by means of correlated quantum-chemical calculations the influence of intermolecular interactions on the absorption and emission properties of conjugated chains. Various strategies are suggested to avoid a substantial decrease in fluorescence quantum yield in condensed media. Finally, the reliability of our theoretical approach is validated by showing the remarkable agreement obtained between the experimental data and the calculated optical properties of clusters formed by sexithienyl molecules.

Electronic Structure and Photophysical Characteristics of Substituted 3-(2-Benzthiazolyl)-Coumarins and Coumarinimines

1987 ◽  
Vol 42 (9) ◽  
pp. 987-993
Author(s):  
P. Nikolova ◽  
N. Tyutyulkova ◽  
V. Dryanska
Keyword(s):  
Electronic Structure ◽  
Quantum Yield ◽  
Quantum Chemical ◽  
Fluorescence Quantum Yield ◽  
Spectral Properties ◽  
High Fluorescence ◽  
High Fluorescence Quantum Yield

The spectral properties of a group of 3-(2-benzthiazolyl)-coumarins and coumarinimines, some of them having high fluorescence quantum yield (Qf > 0.7), are described.The quantum -chemical investigations show that the main chromophore of this group of dyes is the 3 -(2-thiazolyl)-2 H -pyran -2-one fragmenti.e . the coumarin (coumarinimine) and the benzthiazolyl fragments are not separate chromophores.

scholarly journals Tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation

2011 ◽  
Vol 13 (3) ◽  
pp. 12-17 ◽  
Author(s):  
Donka Tasheva ◽  
Sonya Zareva
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Stereoselective Synthesis ◽  
Uv Spectroscopy ◽  
Structural Elucidation ◽  
Butyl Esters ◽  
H Nmr ◽  
Spectroscopic Characteristics

Tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids - stereoselective synthesis, isolation, spectroscopic and structural elucidation A series of seven substituted tert-butyl esters of 2,3-diaryl-3-arylaminopropanoic acids has been synthesized, isolated, spectroscopically and structurally elucidated. An influence of the substituents on the spectroscopic characteristics and conformations is discussed using the data of the linear-polarized IR- (IR-LD), UV-spectroscopy and 1H-NMR. Theoretical quantum chemical calculations are carried out, with a view to explaining and supporting the experimental optical properties and the electronic structure. The stereoselective synthesis of the corresponding diastereoisomers is optimized, thus giving good yields (62-72%) and purity of the compounds

scholarly journals Synthesis of carbon nitride oligomer as a precursor of melon with improved fluorescence quantum yield

2021 ◽  
Vol 2 (18) ◽  
pp. 6083-6093
Author(s):  
Yuto Miyake ◽  
Goichiro Seo ◽  
Kotaro Matsuhashi ◽  
Noriyuki Takada ◽  
Kaname Kanai
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Carbon Nitride

Melem tetramer, the newly synthesized carbon nitride compound is composed of oligomers with four melem units, is stable in air, and has improved optical properties compared to melon.

F-CENTER IMPACT ON PHOTOELECTROCHEMICAL PROPERTIES IN HEMATITE

2010 ◽  
Vol 24 (18) ◽  
pp. 1963-1970 ◽  
Author(s):  
ARVIDS STASHANS ◽  
RICHARD RIVERA
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Oxygen Vacancy ◽  
Quantum Chemical ◽  
Vacancy Defect ◽  
Chemical Model ◽  
Photoelectrochemical Properties ◽  
Structural And Optical Properties ◽  
F Center ◽  
Quantum Chemical Model

Structural and optical properties of F-center (two electrons trapped by an oxygen vacancy) defect in hematite have been studied using a quantum-chemical model. Calculated absorption energies, 0.9 eV and 3.6 eV, are discussed in terms of the available experimental data. An explanation for the origin of experimentally observed electron depletion in hematite is proposed.

scholarly journals Conformational behavior and electronic structure of silylketenes studied with quantum chemical calculations and photoelectron spectroscopy

1997 ◽  
Vol 75 (12) ◽  
pp. 1851-1861 ◽  
Author(s):  
Heidi M. Muchall ◽  
Nick H. Werstiuk ◽  
Jiangong Ma ◽  
Thomas T. Tidwell ◽  
Kuangsen Sung
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Photoelectron Spectroscopy ◽  
Quantum Chemical ◽  
Computational Study ◽  
Photoelectron Spectra ◽  
Conformational Behavior ◽  
Torsional Angle ◽  
Orbital Interaction ◽  
Orbital Energies

The He(I) photoelectron spectra of silylketenes (Me3Si)2C=C=O (1), Me5Si2CH=C=O (2), Me2Si(CH=C=O)2 (3), MeSi(CH=C=O)3 (4), (SiMe2CH=C=O)2 (5), and (CH2SiMe2CH=C=O)2 (6) have been recorded and their structures and orbital energies have been calculated by ab initio methods. Orbital energies for disilanes 2 and 5 are strongly dependent on a Si-Si-C-C torsional angle due to σ–π orbital interaction. Comparisons between experimental and simulated spectra show that 2 and 5 prefer conformations in which the Si—Si bond and ketene group(s) are approximately orthogonal (113° and 111°, respectively). Silylalkenes Me5Si2CH=CH2 (7) and (SiMe2CH=CH2)2 (8), which have been included in the computational study, show the same behavior as their corresponding silylketenes. Silylbis- and trisketenes 3–6 do not exhibit π–π interaction of any significance. For Si—Si containing compounds, the best agreement between experimental and computed data was obtained when Becke3LYP/6-31G*//HF/3-21G* was employed. Keywords: conformational behavior, electronic structure, photoelectron spectroscopy, quantum chemical calculations, silylketenes.

Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olha Zhak ◽  
Oksana Karychort ◽  
Volodymyr Babizhetskyy ◽  
Chong Zheng
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Structure Property Relationships ◽  
Metallic Bonding ◽  
Crystal And Electronic Structure ◽  
Insight Into

Abstract The title compound was prepared from the pure elements by sintering. The crystal structure was investigated by means of powder X-ray diffraction data. Ho5Pd19P12 exhibits the hexagonal Ho5Ni19P12-type structure with space group P 6 ‾ 2 m $P‾{6}2m$ , a = 13.1342(2), c = 3.9839(1) Å, R I = 0.060, R p = 0.080. The crystal structure can be described as a combination of two types of the structural units, [HoPd6P3] and [Ho3Pd10P6], respectively, mutually displaced by 1/2 along the crystallographic c axis. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The results of the quantum chemical calculations indicate that the material features metallic bonding between Ho and Pd and covalent bonding between Pd and P.

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