| Autor: |
Alberto Modelli, Giuseppe Pappalardo, Antonio Grassi, Giuseppe Distefano, Kurt J. Irgolic, Robert A. Pyles |
| Rok vydání: |
1981 |
| Předmět: |
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| Zdroj: |
Journal of Organometallic Chemistry. 220:31-38 |
| ISSN: |
0022-328X |
| DOI: |
10.1016/s0022-328x(00)83101-0 |
| Popis: |
The He(I) photoelectron spectra of dimethyl(phenylthio)arsine and tris-(phenylthio)arsine and dipole moment data on these compounds in benzene at 25°C were used to investigate the molecular conformations of the molecules. Dipole moment analyses showed that dimethyl(phenylthio)arsine is present in solution as an almost equimolar mixture of two conformers in which the CSAs group and the vertical of SCH3CH3As pyramid lie in one plane. The repulsion of the lone electron pairs on the arsenic and sulfur atoms is minimized in these conformers. The dipole moment for tris(phenylthio)arsine indicates a pyrmidal structure of C3υ symmetry for this compound with the phenyl groups pointing in the direction of the arsenic atom at the apex of the pyramid. The four low-energy bands in the photoelectron spectrum of dimethyl(phenylthio)arsine were assigned to the πa(phenyl) orbital (9.22 eV), the nAs orbital (8.78 eV) and the anti-bonding and non-bonding MO's (8.21 eV, 9.75 eV) which were formed by combining the lone pair orbital of sulfur of predominant p-character with the symmetric ring orbitals πsym and π0. The difference of ∼ 1.5 eV between the ionization energies of these anti- and non-bonding MO's is evidence for a non-planar conformation about the C6H5S group. The PE spectrum of tris(phenylthio)arsine is very similar to that of dimethyl(phenylthio)arsine in the low-energy region, and supports the conformation deduced from the dipole moment studies. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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