A thermochemical study of dissociative ionization of 4,4-dimethyl-1-thia-4-silacyclohexane and 2,3,3-trimethyl-1-thia-3-silacyclopentane. Decomposition pathways to produce a dimethylsilanethione ion-radical [Me<sub>2</sub>SiS]<sup>+•</sup>期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

A thermochemical study of dissociative ionization of 4,4-dimethyl-1-thia-4-silacyclohexane and 2,3,3-trimethyl-1-thia-3-silacyclopentane. Decomposition pathways to produce a dimethylsilanethione ion-radical [Me₂SiS]^+•

Authors:	N.A. Tarasenko,V.V. Volkova,V.G. Zaikin,A.I. Mikaya,A.A. Tishenkov,V.G. Avakyan,L.E. Gusel&#x nikov,M.G. Voronkov,S.V. Kirpichenko,E.N. Suslova

Affiliation:	Topchiev Institute of Petrochemical Synthesis of the U.S.S.R. Academy of Sciences, Moscow U.S.S.R.;Irkutsk Institute of Organic Chemistry, Siberian Division of the USSR Academy of Sciences, Irkutsk U.S.S.R.

Abstract:	The dissociative ionization of 4,4-dimethyl-1-thia-4-silacyclohexane (I) and 2,3,3-trimethyl-1-thia-3-silacyclopentane(II) has been studied by electron photoionization (PI) mass spectrometric methods. The molecular ion fragmentation is mainly related to the loss of ethylene and results in a [Me₂SiSC₂H₄]^+? (m/z 118) ion-radical (A). Further loss of ethylene from A produces a dimethylsilanethione [Me₂SiS]^+? (m/z 90) ion-radical (B). The latter is the most abundant ion in the mass spectra of I and II at 70 eV.The ionization energies (IE) of I (8.22 ± 0.07 eV) and II (8.06 ± 0.03 eV) and the appearance energies (AE) of ion-radicals A and B have been determined. Also, the following heats of formation were calculated (kJ/mol): ΔH_f⁰(I) = ?31.1; ΔH_f⁰(II) = ?65.8; ΔH_f⁰(M_I^+?) = 762.0; ΔH_f⁰(M_II^+?)= 712.1; ΔH_f⁰(A)_aver = 780.2; ΔH_f⁰(B)_aver = 847.7.

Keywords:	To whom correspondence should be addressed.
本文献已被 ScienceDirect 等数据库收录！

设为首页 | 免责声明 | 关于勤云 | 加入收藏