Electronic structure of the peptide linkage. II. A molecular orbital treatment of the electronic spectra of benzohydroxamic acids

1985 ◽  
Vol 27 (2) ◽  
pp. 115-133 ◽  
Author(s):  
Rafie Abu-Eittah ◽  
Rifaat Hilal ◽  
Hussein Moustafa
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Electronic Spectra ◽  
Peptide Linkage

A Molecular Orbital Treatment of the Electronic Structure and Spectra of Tautomeric Rhodanines

1978 ◽  
Vol 32 (6) ◽  
pp. 557-563 ◽  
Author(s):  
Rifaat Hilal ◽  
H. Ead ◽  
A. Osman
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Excited States ◽  
Theoretical Investigation ◽  
Electronic Absorption ◽  
Electronic Spectra ◽  
Ph Dependence ◽  
Statistical Distribution ◽  
Tautomeric Equilibria ◽  
Absorption Transitions

An experimental as well as theoretical investigation of the electronic structure and tautomeric equilibria of 2,4-thiazolidinedione, 4-thiazolidinone-2-thione (rhodanine), 2-thiazolidinone-4-thione (isorhodanine) and 2,4-thiazolidinedithione (thiorhodanine) has been conducted. The origin of the electronic absorption transitions and the effect of replacing oxygen by sulfur atoms on coplanarity have been discussed. The solvent and pH dependence of the electronic spectra of the studied compounds indicate that there should be a statistical distribution of the ground and excited states between all possible tautomeric structures. This has been confirmed via molecular orbital computations. The calculated pK values have been interpreted with a mechanism based on the calculated deprotonation energies. Results of the present investigation concur with the chemistry of the studied compounds and reveal that these compounds are far from complete homocyclization.

The effect of ionic lattices on the electronic structures of polyatomic ions. I. The triiodide ion

1966 ◽  
Vol 19 (9) ◽  
pp. 1567 ◽  
Author(s):  
RD Brown ◽  
EK Nunn
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Electron Energy ◽  
Electronic Structures ◽  
Valence Electron ◽  
Bond Orders ◽  
Bond Lengths ◽  
Molecular Orbital Study ◽  
Crystalline Environment ◽  
Asymmetric Stretch

A VESCF molecular-orbital study of the electronic structure of the triiodide anion in its crystalline environment in caesium triiodide and in tetraphenylarsonium triiodide reveals the effect of the lattices upon the electronic structures. The calculated total valence-electron energy as a function of the position of the central iodine nucleus provides an understanding of the observed geometries of the anion in the two crystals. The energy plot also implies that the asymmetric stretch of the triiodide is strongly anharmonic in the crystal. A satisfactory correlation exists between observed iodine : iodine bond lengths and computed bond orders.

A semi-empirical molecular orbital scheme to study electron transfer in iron–sulphur proteins

2005 ◽  
Vol 33 (1) ◽  
pp. 20-21 ◽  
Author(s):  
M. Sundararajan ◽  
J.P. McNamara ◽  
M. Mohr ◽  
I.H. Hillier ◽  
H. Wang
Keyword(s):  
Electron Transfer ◽  
Electronic Structure ◽  
Molecular Orbital ◽  
Parametric Method ◽  
Orbital Method ◽  
Molecular Orbital Method ◽  
Semi Empirical

We describe the use of the semi-empirical molecular orbital method PM3 (parametric method 3) to study the electronic structure of iron–sulphur proteins. We first develop appropriate parameters to describe models of the redox site of rubredoxins, followed by some preliminary calculations of multinuclear iron systems of relevance to hydrogenases.

scholarly journals A Study of Interfacial Electronic Structure at the CuPc/CsPbI2Br Interface

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 547
Author(s):  
Zengguang Tang ◽  
Liujiang Zhang ◽  
Zhenhuang Su ◽  
Zhen Wang ◽  
Li Chen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Energy Gap ◽  
Hole Transport ◽  
Hole Injection ◽  
Band Bending ◽  
Valance Band Maximum ◽  
Interfacial Electronic Structure

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.

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