Synthesis and structure of mixed carboxylate-aminopyridinate and -amidinate complexes of dimolybdenum and ditungsten

Abstract

We describe in this paper the synthesis and structural characterization of dimolybdenum and ditungsten complexes with MM bonds derived from the metal–metal bonded tetracarboxylates [M2(O2CR)4] and incorporating one or two bulky aminopyridinate or amidinate ligands. The new compounds were isolated in good yields from reactions of the [Mo2(O2CR)4] (R=CF3, Me) and [W2(O2CCF3)4] metal precursors with the lithium salts of several aminopyridinate and amidinate ligands. They have formulations [M2(▪)(O2CR)3] or [M2(▪)2(O2CR)2] (▪=bridging aminopyridinate or amidinate ligand) and were identified by microanalysis and common spectroscopic techniques. Nine of the newly reported complexes were additionally characterized by X-ray crystallography.