scholarly journals Interpretation of the Kohn–Sham orbital energies as approximate vertical ionization potentials

2002 ◽  
Vol 116 (5) ◽  
pp. 1760-1772 ◽  
Author(s):  
D. P. Chong ◽  
O. V. Gritsenko ◽  
E. J. Baerends
Keyword(s):  
Ionization Potentials ◽  
Orbital Energies ◽  
Vertical Ionization Potentials

scholarly journals Thermolysis of 2,2-dimethoxy-5,5-dimethyl- Δ3- 1,3,4- oxadiazoline studied with photoelectron spectroscopy. He(I) photoelectron spectrum of dimethoxycarbene

1998 ◽  
Vol 76 (2) ◽  
pp. 238-240
Author(s):  
H M Muchall ◽  
N H Werstiuk ◽  
B Choudhury ◽  
J Ma ◽  
J Warkentin ◽  
...  
Keyword(s):  
Heat Source ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Ionization Potentials ◽  
Perfect Agreement ◽  
Dimethyl Oxalate ◽  
Orbital Energies ◽  
Vertical Ionization Potentials ◽  
Experimental Values

Gas phase thermolysis of 2,2-dimethoxy-5,5-dimethyl- Δ3-1,3,4-oxadiazoline (1) in an ultraviolet photoelectron spectrometer by means of a CW CO2 laser as directed heat source at 26 W gave a complex PE spectrum that included ionization bands belonging to acetone, tetramethoxyethylene (3), and dimethyl oxalate (4). Subtraction of the spectra of acetone, 3, and 4 from the pyrolysis spectrum of 1 left a simple PE spectrum that is attributed to dimethoxycarbene (2) along with some ethane. ecke3LYP/6-31+G* calculations gave first adiabatic and vertical ionization potentials of 2 as well as orbital energies that are in perfect agreement with experimental values. From the available experimental and calculational data, 2 is assumed to adopt a w conformation.Key words: dimethoxycarbene, 2,2-dimethoxy- Δ3-1,3,4-oxadiazoline, tetramethoxyethylene, He(I) photoelectron spectroscopy, thermolysis.

SCF MO CI perturbation calculations of inner shell and valence shell vertical ionization potentials

1978 ◽  
Vol 48 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Hans-Lothar Hase ◽  
G�nther Lauer ◽  
Karl-Wilhelm Schulte ◽  
Armin Schweig
Keyword(s):  
Ionization Potentials ◽  
Valence Shell ◽  
Vertical Ionization Potentials

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.

Vertical Ionization Potentials of Alkoxides in Solution

1994 ◽  
Vol 67 (2) ◽  
pp. 360-362 ◽  
Author(s):  
Kanna Sakai ◽  
Iwao Watanabe ◽  
Yu Yokoyama
Keyword(s):  
Ionization Potentials ◽  
Vertical Ionization Potentials

FREE RADICALS BY MASS SPECTROMETRY: X. THE IONIZATION POTENTIALS OF METHYL SUBSTITUTED ALLYL RADICALS

1956 ◽  
Vol 34 (3) ◽  
pp. 345-353 ◽  
Author(s):  
C. A. McDowell ◽  
F. P. Lossing ◽  
I. H. S. Henderson ◽  
J. B. Farmer
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Electron Impact ◽  
Heat Of Formation ◽  
Ionization Potentials ◽  
Bond Dissociation Energies ◽  
Allyl Radical ◽  
Dissociation Energies ◽  
Allyl Halides ◽  
Vertical Ionization Potentials

The vertical ionization potentials of the β- and γ-methyl substituted allyl radicals as measured by electron impact are 8.03 ± 0.05 v. and 7.71 ± 0.05 v, respectively. From appearance potential data the following bond dissociation energies can be derived, assuming the dissociation processes to be free from complications:[Formula: see text]With assumptions about the structure of the ions produced by electron impact from the corresponding butenes the dissociation energies of the C4H7—H bonds in these latter compounds can be estimated, and the heats of formation of the corresponding radicals derived, namely:[Formula: see text]From data on the allyl halides we evaluate the heat of formation of the allyl radical to be:[Formula: see text]

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