Binding energy shifts for carbon, nitrogen, oxygen, and sulfur core electrons from extended Hueckel theory valence molecular orbital potentials at the nuclei

1972 ◽  
Vol 94 (18) ◽  
pp. 6298-6301 ◽  
Author(s):  
Maurice E. Schwartz ◽  
Jurgen D. Switalski
Keyword(s):  
Binding Energy ◽  
Molecular Orbital ◽  
Valence Molecular Orbital ◽  
Core Electrons

scholarly journals Substitution Effects on the Optoelectronic Properties of Coumarin Derivatives

2019 ◽  
Vol 10 (1) ◽  
pp. 144
Author(s):  
Amit Kumar ◽  
Roberto Baccoli ◽  
Antonella Fais ◽  
Alberto Cincotti ◽  
Luca Pilia ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Optoelectronic Properties ◽  
Exciton Binding Energy ◽  
Basis Set ◽  
Substitution Effects ◽  
Coumarin Derivatives ◽  
Functional Theory

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange–correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application.

The tungsten-tungsten triple bond. 13. Bisalkyl tetracarboxylates of dimolybdenum and ditungsten. Triple bonds between metal atoms with the valence molecular orbital description .pi.4.delta.2

1987 ◽  
Vol 109 (22) ◽  
pp. 6796-6816 ◽  
Author(s):  
Malcolm H. Chisholm ◽  
David L. Clark ◽  
John C. Huffman ◽  
William G. Van der Sluys ◽  
Edward M. Kober ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Triple Bond ◽  
Triple Bonds ◽  
Metal Atoms ◽  
Valence Molecular Orbital

X-ray photoelectron spectroscopic study of hydrated aluminas and aluminas

1994 ◽  
Vol 9 (11) ◽  
pp. 2919-2924 ◽  
Author(s):  
Takeshi Tsuchida ◽  
Hideaki Takahashi
Keyword(s):  
Binding Energy ◽  
Photoelectron Spectra ◽  
Molar Ratio ◽  
Oxygen Species ◽  
X Ray ◽  
Atomic Nuclei ◽  
Valence Electrons ◽  
Core Electrons ◽  
Equal Contribution

X-ray photoelectron spectra of hydrated aluminas (boehmite, diaspore, bayerite, and gibbsite), transition aluminas (y, δ, η, θ, X, and k –Al2O3) and corundum (α-Al2O3) have been studied for spectral characterization of each compound. The O1s spectra are shifted 0.2–1.2 eV to higher binding energy (Eb) in the order of α-Al2O3 < boehmite, diaspore < bayerite, gibbsite, and this agrees with the order of bulk OH/Al molar ratio in samples. The Eb and FWHM values of O1s spectra of transition aluminas depend on the ratio OH/O, i.e., the amount of OH− ions chemisorbed on them, and tend to decrease toward those of α-Al2O3 with increasing calcination temperature. Therefore, it is considered that an attracting effect of the proton on valence electrons in the hydroxyl oxygen causes the increased binding energy between core electrons and oxygen atomic nuclei. The broad O1s spectra of boehmite and diaspore can be deconvoluted into equal contribution from the two oxygen species in O2− and OH− ions in their structures.

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