Amide−Silyl Ligand Exchanges and Equilibria among Group 4 Amide and Silyl Complexes
作者:Hu Cai、Xianghua Yu、Shujian Chen、He Qiu、Ilia A. Guzei、Zi-Ling Xue
DOI:10.1021/ic7010293
日期:2007.9.1
M(NMe2)4 (M = Zr, 1a; Hf, 1b) and the silyl anion (SiButPh2)- (2) in Li(THF)2SiButPh2 (2-Li) were found to undergo a ligand exchange to give [M(NMe2)3(SiButPh2)2]- (M = Zr, 3a; Hf, 3b) and [M(NMe2)5]- (M = Zr, 4a; Hf, 4b) in THF. The reaction is reversible, leading to equilibria: 2 1a (or 1b) + 2 2 <--> 3a (or 3b) + 4a (or 4b). In toluene, the reaction of 1a with 2 yields [(Me2N)3Zr(SiButPh2)2]-[Zr(NMe2)5Li2(THF)4]+
发现Li(THF)2SiButPh2(2-Li)中的M(NMe2)4(M = Zr,1a; Hf,1b)和甲硅烷基阴离子(SiButPh2)-(2)经过配体交换得到[M(在THF中的NMe2)3(SiButPh2)2]-(M = Zr,3a; Hf,3b)和[M(NMe2)5]-(M = Zr,4a; Hf,4b)。该反应是可逆的,导致平衡:2 1a(或1b)+ 2 2 --3a(或3b)+ 4a(或4b)。在甲苯中,1a与2的反应生成[(Me2N)3Zr(SiButPh2)2]-[Zr(NMe2)5Li2(THF)4] +(5)作为离子对。甲硅烷基阴离子2在可逆反应中选择性攻击(Me2N)3Zr-N(SiMe3)2(6a)中的-N(SiMe3)2配体,得到3a和[N(SiMe3)2]-(7):6a + 2 2 <-> 3a +7。还观察到并研究了以下平衡:2M(NMe2)4(1a; 1b)+