用户名: 密码: 验证码:
Dissociative electron attachment to the silane derivatives trichlorovinylsilane (SiCl3C2H3), tetravinylsilane (Si(C2H3)4) and trimethylvinylsilane (Si(CH3)3C2
详细信息查看全文 | 推荐本文 |
摘要
The formation of negative ions following low energy (0-12 eV) electron attachment to the title compounds is studied in a crossed electron-molecular beam experiment applying mass spectrometric detection of the anions. All silane derivatives presently studied are weak electron scavengers which also holds for trichlorovinylsilane. The behaviour in the silanes is hence in strong contrast to the hydrocarbons where chlorination usually results in a strong increase of the cross section for dissociative electron attachment (DEA) yielding intense Cl鈭?/sup> signals already at very low electron energies (near 0 eV). The different behaviour can be explained by the appreciably stronger Si-Cl binding energy compared to that of C-Cl making the DEA reaction leading to Cl鈭?/sup> endothermic for trichlorovinylsilane while the corresponding reaction is exothermic for most chlorinated hydrocarbons. Trichlorovinylsilane and tetravinylsilane undergo various further DEA reactions via different resonances at higher energy (in the range between 4 and 10 eV) leading to a variety of ionic fragments. These reactions range from simple bond cleavages to considerably more complex unimolecular decompositions involving multiple bond cleavages, hydrogen transfer in the temporary negative ion and formation of new bonds. Trimethylvinylsilane yields only one single fragment due to the loss of a neutral hydrogen atom ((M鈭扝)鈭?/sup>).

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700