Synthetic, spectroscopic and magnetic studies of heterometal alkoxides of cobalt(II, nickel(II) and copper(II) containing the sterically crowded tetraalkoxoaluminate ligand

Abstract

Heterobimetallic alkoxides of the types [ClM{Al(OBu^t)₄}] (I) and [M{Al(OBu^t)₄}₂] (II) (M = Co^II, Ni^II and Cu^II) have been prepared by the interactions of MCl₂ with K{Al(OBu^t)₄} in 1:1 and 1:2 molar ratios, respectively. These chloro(tetra-t-butoxoaluminato) complexes proved to be useful precursors for the synthesis of a variety of bimetallic alkoxo derivatives such as: [(OBu^t)M{Al(OBu^t)₄}], [{Al(OEt)₄}M {Al(OBu^t)₄}] and [{Al(OPrⁱ)₄}M and {Al(OBu^t)₄}]. All these derivatives are highly moisture-sensitive, coloured solids or viscous liquids. Most of these are volatile except the mixed derivatives like [ClM{Al(OBu^t)₄}] and [(OBu^t)M{Al(OBu^t)₄}] which tend to disproportionate on heating. These heterometal alkoxides have been characterized by elemental analyses, spectroscopic (IR and visible) and magnetic studies, as well as molecular weight determinations.