Complexation and Exchange Reactions of some Dimethylamino-substituted Group 4 Compounds

Article abstract of DOI:10.1039/DT9810001264

Reactions of CH2(NMe2)2, (1), SiMe2(NMe2)2, (2), (cp=η-cyclopentadienyl), (3), and , (4), with covalent metal halides MCl4 (M=Ti,Zr,Si,Ge,or Sn) and MCl3 (M=Ti,V,or Cr) fall into two categories: (a) N-donor chelation leading to complex formation and (b) halide-NMe2 exchange.Compound (1) gives 1:1 complexes with MCl4 (M=Ti or Sn) and 2:1 complex with VCl3.Compound (2) provides 1:1 complexes with MCl4 (M=Ti,Zr,Hf, or Sn).The decomposition of TiCl4*SiMe2(NMe2)2 --> invariably occurs in both the solid state and solution.There is no reaction of (2) with metal(III) chlorides.With MCl4 (M=Si or Ge 'scrambling' reactions involving halide-NMe2 exchange occur and these have been monitored by ¹H n.m.r. spectroscopy.Reactions of (3) and (4) with MCl4 (M=Si,Ge,Sn,Ti,Zr,or Hf) consistently feature halide-NMe2 exchange rather than adduct formation.All complexes have been characterised by analytical and spectroscopic (¹H n.m.r. and i.r.) investigations.