A chelate-stabilized tungsten-bis(imido) complex

The title compound, [N,N'-bis(trimethylsilyl)-6,6'-dimethylbipheny]-2,2'-di amido]bis(2,6-diisopropylphenylimido)tungsten(VI),[W(C12H17N)(2)(C20H30N2Si 2)], has been synthesized and its crystal structure determined. The geometr y around the W atom, imposed by the biphenyldiamido and bulky 2,6-diisoprop ylphenylimido ligands, is that of a tetrahedron. As a result of this geomet ry, the biphenyl group is twisted, with a dihedral angle of 69.65 (8)degree s. Principal distances include W-N(imido) 1.762 (2) and 1.772 (2) Angstrom, and W-N(amido) 1.976 (2) and 1.984 (2) Angstrom.