A series of molybdenum(VI) complexes with tridentate Schiff base ligands

Mononuclear and polynuclear dioxomolybdenum(VI) complexes with Schiff base ligands have been prepared by the reaction of [MoO2(acac)(2)] with salicylaldehyde (1 and 4), 2-hydroxy-1-naphthaldehyde (2 and 5) and 2-hydroxy-3-methoxybenzaldehyde (3 and 6) with addition of appropriate amine. All prepared complexes of the general formulae [MoO2LD] and [MoO2L](n) consist of cis-MoO22+ core coordinated by Schiff-base ligand (L) in a tridentate manner through two deprotonated hydroxyl groups and one imino nitrogen. The usual octahedral coordination around molybdenum atom is completed by monodentate solvent molecules D (methanol, ethanol or dimethylsulphoxide). All compounds were characterized by means of chemical analysis, IR spectroscopy, thermogravimetric analysis and some of them by X-ray crystallography (1a, 2c, 3a, 4c and 6c).