title: Ionic S(N)i-Si Nucleophilic Substitution in N-Methylaniline-Induced Si-Si Bond Cleavages of Si2Cl6.
abstract: N-Methylaniline-induced Si-Si bond cleavage of Si2Cl6 has been theoretically studied. All calculations were performed by using DFT at the MPWB1K/6-311++G(3df,2p)//MPWB1K/6-31+G(d,p) levels. An ionic SN i-Si nucleophilic substitution mechanism, which is a newly found nucleophilic substitution in silicon-containing compounds, is proposed in the N-methylaniline-induced Si-Si bond cleavage in Si2Cl6. Unlike general S(N)i-Si nucleophilic substitutions that go through a pentacoordinated silicon transition state, ionic nucleophilic substitution goes through a tetracoordinated silicon transition state, in which the Si-Si bond is broken and siliconium ions are formed. Special cleavage of the Si-Si bond is presumably due to the good bonding strength between Si and N atoms, which leads to polarization of the Si-Si bond and eventually to heterolytic cleavage. Calculation results show that, in excess N-methylaniline, the final products of the reaction, including (NMePh)(3-n) SiHCl(n) (n=0-2) and (NMePh)(4-n) SiCl(n) (n=2-3), are the Si-Si cleavage products of Si2Cl6 and the corresponding amination products of the former. The ionic S(N)i-Si nucleophilic substitution mechanism can also be employed to describe the amination of chlorosilane by N-methylaniline. The suggested mechanisms are consistent with experimental data.
authors.affiliation: Key Laboratory of Special Functional Aggregated Materials and, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Jie
authors.identifier: http://orcid.org/0000-0002-1716-1877
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, P.R. China.
authors.forename: Ju
authors.initials: J
authors.lastname: Xie
authors.affiliation: Department of Chemistry and Medical Chemistry, College of Science and Technology, Research and, Education Center for Advanced Silicon Materials, Yonsei University, Wonju, Gangwon-do, 220-710, South Korea.
authors.forename: Myong Euy
authors.initials: ME
authors.lastname: Lee
authors.affiliation: Key Laboratory of Special Functional Aggregated Materials and, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Special Functional Aggregated Materials and, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: Key Laboratory of Special Functional Aggregated Materials and, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Shengyu
authors.initials: S
authors.lastname: Feng
keywords: bond theory; density functional calculations; nucleophilic substitution; reaction mechanisms; silanes