Correlation of H�ckel molecular orbital energies with ?-ionization potentials

1972 ◽  
Vol 26 (4) ◽  
pp. 289-299 ◽  
Author(s):  
F. Brogli ◽  
E. Heilbronner
Keyword(s):  
Molecular Orbital ◽  
Ionization Potentials ◽  
Orbital Energies

Photoelectron spectra of 4-substituted stilbenes

1978 ◽  
Vol 56 (21) ◽  
pp. 2714-2719 ◽  
Author(s):  
E. J. McAlduff ◽  
Tammy Chan
Keyword(s):  
Gas Phase ◽  
Molecular Orbital ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Rate Data ◽  
Planar Configuration ◽  
Orbital Energies

The photoelectron spectra of stilbene and 4-R-stilbene (R = CH3O, CH3, F, Cl, NO2) has been determined and the five highest Π ionization potentials assigned. By considering the stilbenes to be formally constituted by union of a styrene and substituted benzene the influence of substituent on molecular orbital energies gas been rationalized. The data suggest that the stilbenes exist in a planar or nearly planar configuration in the gas phase. CNDO/2 calculations have been performed on a wider variety of 4-R-stilbenes (R = NH2, CH3, OH, F, CN, CF3, NO2) and it is suggested that planar configurations also predominate for those stilbenes. First ionization potentials of some of the stilbenes are correlated with bromination and ozonolysis rate data.

ChemInform Abstract: TEMO. PART 10. THE EFFECT OF MOLECULAR TOPOLOGY ON Π-MOLECULAR-ORBITAL ENERGIES

1985 ◽  
Vol 16 (30) ◽  
Author(s):  
I. MOTOC ◽  
J. N. SILVERMAN ◽  
O. E. POLANSKY ◽  
G. OLBRICH
Keyword(s):  
Molecular Orbital ◽  
Molecular Topology ◽  
Orbital Energies

A Discussion on photoelectron spectroscopy - Orderings of π and σ ionization potentials in carbocyclic and heterocyclic aromatic compounds

1970 ◽  
Vol 268 (1184) ◽  
pp. 131-140 ◽  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Aromatic Compounds ◽  
Lone Pair ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Light Sources ◽  
Orbital Energies ◽  
Substituted Pyridines ◽  
Nitrogen Lone Pair ◽  
Electron Correlation Effects

Data on calculated orbital energies and experimentally measured ionization potentials of carbocyclic and heterocyclic aromatic compounds are compared and contrasted. The ordering or orbital energies and ionization potentials do not always seem to parallel one another, probably owing to either electron correlation effects, or to deviations from Koopman’s theorem. The effects on photoelectron spectra of using different light sources and analysers are discussed in relation to their bearing on the orbital orderings of aromatic compounds. The high resolution He 584 A. photoelectron spectrum of pyridine is shown to be open to two interpretations regarding the ordering of the ionization potentials of the π orbitals and the ‘nitrogen lone pair’ (n). One of the interpretations involves the three lowest pyridine ionization potentials being π (9.2 eV), π L (9.5 eV) and n (10.5 eV) whilst the other has the first three ionization potentials being the order π , n, π . The photoelectron spectra of substituted pyridines and diazines are discussed in the light of the two possible explanations for the pyridine spectrum.

Photoelectron Spectrum and Electronic Structure of Tetrathiofulvalene (TTF)

1974 ◽  
Vol 52 (19) ◽  
pp. 3373-3377 ◽  
Author(s):  
A. John Berlinsky ◽  
James F. Carolan ◽  
Larry Weiler
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Molecular Orbital ◽  
Photoelectron Spectrum ◽  
Crystal Packing ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Molecular Orbital Calculations ◽  
Conducting Salt

The electronic structure of tetrathiofulvalene (TTF) has been determined from its photoelectron spectrum and the photoelectron data for the tetrahydro derivative of TTF and 1,3-dithiolane. Correlations of the ionization potentials (i.p.) and several molecular orbital calculations are used in the assignment of the photoelectron spectra of these three compounds. The first five i.p. of TTF and their assignment are as follows: 6.92 (3b1u), 8.67 (2b2g), 9.73 (2b1u), 10.16 (au) and 10.49 eV (b3g). The sixth i.p. at 11.00 eV is tentatively assigned to the 1b2g level. The electronic structure of TTF is important in understanding the crystal packing and band structure of the highly conducting salt, TTF•TCNQ.

scholarly journals Breit corrections to individual atomic and molecular orbital energies

2018 ◽  
Vol 148 (4) ◽  
pp. 044113 ◽  
Author(s):  
Karol Kozioł ◽  
Carlos A. Giménez ◽  
Gustavo A. Aucar
Keyword(s):  
Molecular Orbital ◽  
Orbital Energies

Inductive Effects on Molecular Ionization Potentials, XVIII Alkylpyridines and Alkylthiophenes. Molecular Orbital Calculations on Alkylbenzenes and Alkylpyridines

1977 ◽  
Vol 32 (10) ◽  
pp. 1160-1164 ◽  
Author(s):  
Cyril Párkányi ◽  
Leonard S. Levitt
Keyword(s):  
Molecular Orbital ◽  
Linear Correlation ◽  
Molecular Orbitals ◽  
Ionization Potentials ◽  
Molecular Orbital Calculations ◽  
Alkyl Groups ◽  
Inductive Effects ◽  
Substituent Constants ◽  
Linear Correlations ◽  
Molecular Ionization

Models of alkylbenzenes were treated by the HMO and SCF—MO methods and excellent linear correlations were found between the experimental ionization potentials, EI, and the energies of the highest occupied π-molecular orbitals calculated by the above-mentioned methods. A similar linear correlation was obtained for a group of methylpyridines. Also, the experimental ionization potentials of methylpyridines and alkylthiophenes have been linearly correlated with the sum of TAFT'S inductive substituent constants, ΣσI of the alkyl groups.

Sign in / Sign up

Export Citation Format

Share Document