A Series of New Molybdenum(VI) Complexes with the ONS Donor Thiosemicarbazone Ligands

New dioxomolybdenum(VI) complexes were obtained by the reaction of [MoO2(acac)2] with 4‐phenylthiosemicarbazone ligands derived from salicylaldehyde, 2‐hydroxy‐1‐naphthaldehyde, 2‐hydroxy‐3‐methoxybenzaldehyde or from 4‐(diethylamino)salicylaldehyde. In all complexes the ligands are coordinated to molybdenum as tridentate ONS‐donors through phenolic‐oxygen, imine‐nitrogen and thiol‐sulphur. Octahedral coordination of each Mo atom is completed either by one neutral donor molecule (D) or by the oxygen atom of the Mo=O unit from the neighbouring molecule. All compounds were characterized by means of chemical analysis, IR spectroscopy, TG and in some cases by DSC measurements, some of them by X‐ray crystallography, and by one and two‐dimensional NMR method.