A Mixed‐Valence Tri‐Zinc Complex, [LZnZnZnL] (L=Bulky Amide), Bearing a Linear Chain of Two‐Coordinate Zinc Atoms

Reduction of a variety of extremely bulky amido Group 12 metal halide complexes, [LMX(THF) 0,1 ] (L=amide; M=Zn, Cd, or Hg; X=halide) with a magnesium(I) dimer gave a homologous series of two‐coordinate metal(I) dimers, [L′MML′] (L′=N(Ar † )(SiMe 3 ), Ar † =C 6 H 2 {C(H)Ph 2 } 2 Pr i ‐2,6,4); and the formally zinc(0) complex, [L*ZnMg( Mes Nacnac)] (L*=N(Ar*)(SiPr i 3 ); Ar*=C 6 H 2 {C(H)Ph 2 } 2 Me‐2,6,4; Mes Nacnac=[(MesNCMe) 2 CH] − , Mes=mesityl), which contains the first unsupported ZnMg bond. Two equivalents of [L*ZnMg( Mes Nacnac)] react with ZnBr 2 or ZnBr 2 (tmeda) to give the mixed valence, two‐coordinate, linear tri‐zinc complex, [L*Zn I Zn 0 Zn I L*], and the first zinc(I) halide complex, [L*ZnZnBr(tmeda)], respectively. The analogues [L*ZnMZnL*] (M=Cd or Hg), were also prepared, the Cd species contains the first ZnCd bond in a molecular compound. Metal–metal bonding was studied by DFT calculations.