Synthesis and Characterization of Group 12 Metal(I) Complexes Bearing Extremely Bulky Boryl/Silyl Substituted Amide Ligands

Two extremely bulky boryl/silyl-substituted amide ligands, -N{B(DipNCH)(2)}(SiR3) (R = Me L-TBo, R = Ph L-PhBo; Dip = 2,6-diisopropylphenyl) were used in the preparation of the group 12 metal halide complexes, (LZnBr)-L-PhBo, {(LCd)-L-TBo(mu-I)}(2), (LHgI)-L-TBo, and (LHgI)-L-PhBo. The reduction of these, and two previously reported compounds, (LZnBr)-L-PhBo(THF) and {(LCd)-L-PhBo(mu-I)}(2), using a magnesium(I) compound, {((Mes)Nacnac)Mg}(2) ((Mes)Nacnac = [(MesNCMe)(2)CH](-), Mes = mesityl), were carried out, leading to mixed results. In several cases these reactions led to decomposition, and deposition of the group 12 metal. However, in two instances the homobimetallic metal(I) complexes, (LM)-L-TBo-(ML)-L-TBo (M = Zn or Hg), were isolated and crystallographically characterized. The reduction of {(LCd)-L-PhBo(mu-I)}(2) afforded the known cadmium(I) complex, (LCd)-L-PhBo-(CdL)-L-PhBo, but also gave a very low yield of the thermally unstable complex, (LCd)-L-PhBo-Mg(THF)((Mes)Nacnac). The X-ray crystal structure of this compound reveals it to contain the first example of a Cd-Mg bond in a molecular compound.