Photoelectron spectra of 3-substituted cyclopentenes. Correlations between ionization potentials and cycloaddition regioselectivity

1978 ◽  
Vol 100 (1) ◽  
pp. 105-110 ◽  
Author(s):  
E. J. McAlduff ◽  
Pierluigi Caramella ◽  
K. N. Houk
Keyword(s):  
Ionization Potentials ◽  
Photoelectron Spectra

Photoelectron spectra and molecular properties. Scil2-ionization potentials and AB initio SCF calculations

1974 ◽  
Vol 26 (1) ◽  
pp. 20-24 ◽  
Author(s):  
B. Solouki ◽  
P. Rosmus ◽  
H. Bock
Keyword(s):  
Ab Initio ◽  
Molecular Properties ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Scf Calculations

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.

Ionization potentials and intramolecular charge transfer. Photoelectron spectra of chloromethyl and methyl alkyl ethers

1986 ◽  
Vol 27 (2) ◽  
pp. 230-235
Author(s):  
V. V. Zverev ◽  
A. A. Bredikhin ◽  
V. M. Vakar' ◽  
A. N. Vereshchagin
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Alkyl Ethers

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.

The Photoelectron Spectra the Chloro Toluenes

1987 ◽  
Vol 40 (4) ◽  
pp. 751 ◽  
Author(s):  
JB Peel ◽  
EI Vonnagyfelsobuki
Keyword(s):  
Ab Initio ◽  
Cross Section ◽  
Valence Electron ◽  
Model Potential ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Molecule Model ◽  
Linear Correlations ◽  
Spectral Assignment

The HeI and HeII photoelectron spectra of the chloro toluenes have been measured. The spectra are assigned using HeI/HeII cross-section ratios and a composite-molecule model within an ab initio valence-electron-only model potential (VEOMP) framework. The order of the first two ionization potentials for the chloro toluenes is assigned as πS < πA which is contrary to the VEOMP assignment for benzal chloride and benzotrichloride , but is consistent with linear correlations using group electronegativities and σI scales. Furthermore, linear correlations using the first two ionization potentials of fluoro and chloro toluenes with group electronegativities are shown to be a useful aid in spectral assignment and, moreover, suggest that for benzyl fluoride and benzal chloride the most appropriate σI values are 0.20 and 0.31 respectively.

ChemInform Abstract: PHOTOELECTRON SPECTRA AND MOLECULAR PROPERTIES. LI. IONIZATION POTENTIALS OF SILANES SINH2N+2

1976 ◽  
Vol 7 (18) ◽  
pp. no-no
Author(s):  
H. BOCK ◽  
W. ENSSLIN ◽  
F. FEHER ◽  
R. FREUND
Keyword(s):  
Molecular Properties ◽  
Ionization Potentials ◽  
Photoelectron Spectra

A Discussion on photoelectron spectroscopy - Photoelectron studies of boron compounds I. Diborane, borazine and B-trifluoroborazine

1970 ◽  
Vol 268 (1184) ◽  
pp. 97-109 ◽  
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Molecular Orbitals ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Energy Separation ◽  
Hydrogen Bridge ◽  
Boron Compounds ◽  
Vertical Ionization Potentials

The photoelectron spectra of diborane, hexadeuterodiborane, borazine and B -trifluoroborazine are presented, and adiabatic and vertical ionization potentials have been measured. The vibrational fine structure observed on some of the diborane bands is shown to be consistent with the forms of the molecular orbitals calculated by rigorous s.c.f. methods. The vertical i.p. of diborane are in better accord with a calculation which predicts a boron-boron bond in addition to the hydrogen bridge than with the calculations which indicate no direct boron-boron interaction. In borazine it is shown that the uppermost orbital is of π type rather than the σ type predicted by calculations, and that the extent of the π bonding, as measured by the energy separation of the π-type orbitals, is about 85 % of that in benzene. The effect of fluorination of borazine, as in benzene, is to stabilize the σ orbitals more than the π orbitals.

Photoelectron Spectra and Bonding in Some Halosilanes

1971 ◽  
Vol 49 (24) ◽  
pp. 4033-4046 ◽  
Author(s):  
D. C. Frost ◽  
F. G. Herring ◽  
A. Katrib ◽  
R. A. N. McLean ◽  
J. E. Drake ◽  
...  
Keyword(s):  
Bond Strength ◽  
Ionization Potentials ◽  
Photoelectron Spectra ◽  
Ample Evidence ◽  
Carbon Compounds ◽  
Back Bonding ◽  
The Individual ◽  
D Orbitals

The photoelectron spectra of some halosilanes, SiH3X (X = F, Cl, Br), SiH2X2 (X = F, Cl), and SiHCl3 have been studied, to obtain information on the bonding, especially (p → d)π back-bonding to silicon. The spectra were assigned on simple orbital overlap grounds, by comparison with the carbon analogues and by use of CNDO/2 calculations. Few discrepancies were found, but in these cases the first method was preferred. There is ample evidence from the individual ionization potentials and by comparison of the spectra with those of the analogous carbon compounds for interaction of the halogen pπ electrons with the silicon d orbitals. This is also indicated by some empirical calculations on the chlorosilanes, which also confirm the assignment of the spectra.It can also be shown that the ionization potentials are consistent with the silicon–halogen σ bond strength decreasing through the series H3SiF > H3SiCl > H3SiBr.

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