The Effect of Si d-Orbital in the Ion/Molecule Reactions of Organosilicon

这项研究的目的是为有机硅阳离子和阴离子的简单重排提供证据，并阐明在没有金属原子的有机化合物中没有观察到的特定反应的机理和影响因素。用FTICR质谱仪研究了硅烯阳离子自由基与烯烃分子的离子/分子反应。1-二甲基-1-硅环丁烷和L，1-[D6]-二甲基-1-硅环丁烷经70 eV电子电离生成了硅烯阳离子自由基[(CH3)2SiCH2]^+和[(CD3)2SiCH2]+。在FTICR池中分离出这些硅烯阳离子自由基后，它们被允许在超高真空条件下(10^&lt；-8&gt；-10^&lt；-9&gt；mbar)与乙烯、[4]乙烯或丙烯分子反应。FTICR谱表明，在离子/分子反应中产生的加合离子应该具有四元环结构。用Bruker Apex；TM+&GT；47E FT-ICR质谱仪和JEOL JMS SX/SX 102a四区串联质谱仪研究了2-金刚烷基-4-叔丁基-2-三甲基硅氧基-1，1-二(三甲基硅基)-L-硅环-3-烯的电子碰撞电离(EI)、化学电离(CI)和快离子轰击电离(CI)，以生成含碳化硅双键或三键的离子。高分辨质量测量结果表明，在m/z 330处碎片离子的元素组成为C&lt；20&gt；H&lt；34&gt；Si_2^+。MS/MS/MS和从头算计算结果表明，m/z330离子是一个含有Si=C双键的四元环。

The purpose of this study is to provide evidence for a facile rearrangement of organosilicon cations and anions and to clarify the mechanisms and the effective factors in the specific reactions which are not observed in organic compounds without metallic atoms.1. Ion/molecule reactions of silene cation radicals with alkene molecules were investigated using FTICR mass spectrometry. The silene cation radicals [(CH_3)_2SiCH_2]^+ and [(CD_3)_2SiCH_2]+ were generated by 70 eV-electron ionization of 1-dimethyl-1-silacyclobutane and l, 1-[D_6]dimethyl-1-silacyclobutane. After these silene cation radicals were isolated in the FTICR cell, they were allowed to react with ethene, [_4]ethene, or propene molecules under ultra-high-vacuum conditions (l0^<-8>-l0^<-9> mbar). The resulting FTICR spectra show that the adduct ions, produced in the ion/molecule reactions, should have a four-membered ring structure.2. In order to make an SiC multiple bond, an electron-impact ionization (EI), a chemical ionization (CI) and a fast-ion-bombardment ionization of 2-adamantyl-4-tert-butyl-2-trimethylsiloxy- 1,1-bis(trimethylsilyl)- l-silacyclobut-3-ene were examined in order to generate ions containing an SiC double or triple bond using both a Bruker Apex^<TM+> 47e FT-ICR mass spectrometer and a JEOL JMS SX/SX 1 02A four-sector tandem mass spectrometer. From the results of high-resolution mass measurement, the elementary composition of fragment ions at m/z 330 was found to be C_<20>H_<34>Si_2^+. The results of MS/MS/MS and ab initio MO calculations showed that the structure of the m/z 330 ion is a four-membered ring containing an Si=C double bond.