Synthesis of Tungsten and Molybdenum Carbon Dioxide Complexes

Abstract

Tungsten and molybdenum η 2 -CO 2 complexes of the form TpM(NO)(L)(η 2 -CO 2 ), where M = W, Mo, Tp = tris(pyrazolyl)borate, and L = PMe 3, 1-methylimidazole, have been synthesized by displacement of an η 2 -aromatic ligand under elevated CO 2 pressure. These complexes have been characterized by single-crystal X-ray diffraction. The η 2 -CO 2 complexes are air stable and resist decomposition in solution. In addition, the molybdenum η 2 -CO 2 complex undergoes chemical reduction of the η 2 -CO 2 ligand to form TpMo(NO)(1-methylimidazole)(CO).