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

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.Ministerio de Ciencia e Innovación CTQ2010-15833, CTQ2011-23862-C02-01, Consolider-Ingenio 2010 CSD2007-0000Junta de Andalucía FQM-119, P09-FQM-511