Improved first ionization potential of the dimethylsilaethylene molecule obtained with high-temperature photoelectron spectroscopy

1982 ◽  
Vol 86 (15) ◽  
pp. 2913-2916 ◽  
Author(s):  
J. M. Dyke ◽  
G. D. Josland ◽  
R. A. Lewis ◽  
A. Morris
Keyword(s):  
High Temperature ◽  
Ionization Potential ◽  
Photoelectron Spectroscopy ◽  
First Ionization Potential

Electronic Levels of Methyl Amines by Photoelectron Spectroscopy and an i.n.d.o. Calculation

1971 ◽  
Vol 49 (7) ◽  
pp. 1135-1136 ◽  
Author(s):  
A. B. Cornford ◽  
D. C. Frost ◽  
F. G. Herring ◽  
C. A. McDowell
Keyword(s):  
Binding Energy ◽  
Ionization Potential ◽  
Photoelectron Spectroscopy ◽  
Lone Pair ◽  
Ionization Potentials ◽  
The One ◽  
First Ionization Potential

The ionization potentials of the methyl amines down to 20 eV binding energy, have been determined by photoelectron spectroscopy, and are compared with those predicted by i.n.d.o.-l.c.a.o.-s.c.f. theory. The first ionization potential for each compound refers to the removal of an electron from the lone pair, and is shown to be the one most affected by the inclusion of one center repulsion integrals in the i.n.d.o. calculations.

Photoelectron spectroscopy of hydrogen-bonded systems: spectra of monomers, dimers and mixed complexes of carboxylic acids

1972 ◽  
Vol 331 (1585) ◽  
pp. 249-261 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Ionization Potential ◽  
Carboxylic Acids ◽  
Photoelectron Spectroscopy ◽  
Free Acid ◽  
Photoelectron Spectra ◽  
Target Chamber ◽  
Donor Group ◽  
Mixed Complexes ◽  
First Ionization Potential

By cooling the target chamber of a photoelectron spectrometer, the photoelectron spectra of dimers and mixed complexes of carboxylic acids have been obtained. By comparison of the spectra with each other and with those of the monomers, it has been possible to assign several bands to ionization from specific molecular orbitals. Hydrogen-bonding changes most ionization potentials of the monomers but not by more than about 0.5 eV. In particular, the ionization potential of an electron from a non-bonding orbital on the proton donor group is decreased and that from a non-bonding orbital on the electron donor group is increased. This is consistent with most theories of hydrogen bonding. In the mixed complexes it makes the first ionization potential higher than that of the free acids, dimers, however, are complicated by the initial degeneracy of their orbitals and this results in their first ionization potential being lower than for the free acid. There is also some evidence that the hydrogen bonds in a complex between different acids are of unequal strength.

Article

1998 ◽  
Vol 76 (2) ◽  
pp. 221-227
Author(s):  
Heidi M Muchall ◽  
Nick H Werstiuk ◽  
Biswajit Choudhury
Keyword(s):  
Ionization Potential ◽  
Photoelectron Spectroscopy ◽  
Quantum Chemical ◽  
Lone Pair ◽  
Basis Sets ◽  
Eigenvalues And Eigenvectors ◽  
Adiabatic Ionization Potential ◽  
Experimental Values ◽  
Ab Initio Hf ◽  
First Ionization Potential

Photoelectron (PE) spectra of two stable carbenes 7 and 8 have been recorded and the spectra have been interpreted with the aid of eigenvalues and eigenvectors taken from Becke3LYP calculations. For the carbene series 6-8, the lone pair on the carbene carbon atom is the HOMO. The first adiabatic ionization potential (IP) of eight electronically quite different carbenes has been calculated using semiempirical PM3 and ab initio HF, Becke3LYP, and Becke3PW91 methods (3-21G(*) and 6-31+G* basis sets) as well as the CBS-4 model. For the first vertical IP, the HAM/3, Becke3LYP, and Becke3PW91 methods have been employed. CBS-4 and DFT calculations show excellent agreement with experimental values. Considering both accuracy and speed, the method of choice for the prediction of first ionization potentials of carbenes seems to be Becke3LYP/6-31+G*//Becke3LYP/3-21G(*).Key words: carbenes, electronic structure, first ionization potential, photoelectron spectroscopy, quantum chemical calculations.

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