Ni(II) complexes with thioether-functionalized silylamide ligands. Synthesis and crystal structures of [Ni{Me2Si(N-C6H4-2-S-t-Bu)2}], [Ni{Ph2Si(N-C6H4-2-SMe)2}] and [Ni{Ph2Si(N-C6H4-2-SPh)2}]

Abstract

Abstract Thioether-functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with R=Me, Ph and R′=t-Bu, Me, Ph were synthesized from the corresponding dichlorosilanes R2SiCl2 and lithiated aniline derivatives LiNH-C6H4-2-SR′. Treatment of the functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with two eq. of n-BuLi and subsequent reaction with nickel(II) halides NiX2 (X=Cl, Br) or [Ni(acac)2(TMEDA)] led to the formation of the Ni(II) complexes [Ni{R2Si(N-C6H4-2-SR′)2}]. The X-ray single-crystal structure determinations of the nickel complexes revealed that the thioether-functionalized silylamides R2Si(NC6H4-2-SR′)2 2− act as tetradentate ligands. The nickel atoms exhibit a distorted square-planar coordination with Ni–N and Ni–S bond lengths in the range of 186.4(3)–186.9(2) pm and 217.5(1)–221.5(1) pm, respectively.