Derivatives of Group 4 metal amide chlorides and fluorides: Synthesis, structure and characterization of novel dimethyl and fluoro-chloro complexes

Reaction of MgMeBr with [MCl(2)L(2)] and [MCl(2)(eta-C(5)Me(5))L] [L = (2,6-(Pr2C6H3)-C-1)N(SiMe(3)), M = Zr or Hf] gave the corresponding dimethyl complexes [MMe(2)L(2)] (M = Zr 1a or Hf 1b) and [MMe(2)(eta-C(5)Me(5))L] (M = Zr 2a or Hf 2b). Reaction of [ZrF(2)L(2)] with AlMe(3) also yielded 1a. The structures of 1a and 2a have been determined by single-crystal X-ray crystallography. Upon reaction of 1 molar equivalent of SnMe(3)F with [MCl(2)L(2)] and [MCl(2)(eta-C(5)Me(5))L] mixed fluoro-chloro complexes, [MCl(F)L(2)] (M = Zr 3a or Hf 3b) and [MCl(F)(eta-C(5)Me(5))L] (M = Zr 4a or Hf 4b) were formed, via elimination of SnMe(3)Cl. The structure of 4a has been determined by single-crystal X-ray analysis.