Ab initio study of molecular structure and internal rotation in methyldicyanophosphine and methyldiisocyanophosphine. The Raman spectrum of methyldicyanophosphine and its interpretation with the use of scaling ofab initio force fields |
| |
Authors: | L. S. Khaikin O. E. Grikina B. I. Zhilinskii E. A. Zhilinskaya E. G. Baskir R. V. Nepomnyashchii O. A. Fomicheva M. V. Proskurnina |
| |
Affiliation: | (1) Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory, 119899 Moscow, Russian Federation;(2) Littoral University, F-59140 Dunkirk, France;(3) N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 117913 Moscow, Russian Federation;(4) Present address: Universite du Littoral, F-59140 Dunkerque, France |
| |
Abstract: | The equilibrium geometric parameters and structures of transition states of internal rotation for the molecules of methyldicyanophospine MeP(CN)2 and its isocyano analog MeP(NC)2 were calculated by the RHF and MP2 methods with the 6–31G* and 6–31G** basis sets. At the MP2 level, the total energy of cyanide is −35 kcal mol−1 lower than that of isocyanide and the barriers to internal rotation of methyl group for MeP(CN)2 and MeP(NC)2 are 2.2 and 2.7 kcal mol−1, respectively. For both molecules, the one-dimensionalab initio potential functions of internal rotation approximated by a truncated Fourier series were used to determine the frequencies of torsional transitions by solving direct vibrational problems for a non-rigid model. The Raman spectrum of crystalline MeP(CN)2 was recorded in the range 3500–50 cm−1. The vibrational spectra of this compound were interpreted by scalingab initio force fields calculated by the RHF and MP2 method. The vibrational spectrum of methyldiisocyanophosphine was predicted with the use of the obtained scale factors. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1703–1714, September, 1998. |
| |
Keywords: | methyldicyanophosphine methyldiisocyanophosphine ab initio calculations molecular structure, internal rotation vibrational spectra |
本文献已被 SpringerLink 等数据库收录! |
|