New Molybdenum(VI) Complexes with Thiosemicarbazone Ligands Containing 4-hydroxy-2-pyrone Ring

Višnja Vrdoljak,a,* Biserka Prugovečki,a Marina Cindrić,a Dubravka Matković-Čalogovića and Ana Brbot-Šaranović

a Laboratory of General and Inorganic Chemistry, Chemistry Department, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia.
* Corresponding author: E-mail:

New molybdenum(VI) complexes have been prepared by the reaction of [MoO2(acac)2] (acac = acetylacetonate ion) with the thiosemicarbazone ligands derived from dehydroacetic acid and thiosemicarbazide (H2L1) or 4-phenylthiosemicarbazide (H2L2). All complexes consist of the MoO22+ core with molybdenum coordinated by ligand L via three donor atoms: pyran-4-ol-oxygen, imine-nitrogen and thiol-sulphur. Unlike the monomeric complexes [MoO2L2D], where the octahedral coordination around the molybdenum atom is achieved by additional coordination of one neutral solvent molecule D (methanol in 2a or ethanol in 2b), in the polymeric complexes [MoO2L]n (1 and 2) the octahedral coordination is accomplished by an intermolecular metaloxygen interaction (metal...oxygen//Mo=O···Mo=O). All compounds were characterized by means of elemental analyses, IR spectra, thermal analysis and some of them by X-ray crystallography (ligand HL1 and complex 2b).

Keywords: Molybdenum(VI) complexes; dehydroacetic acid, thiosemicarbazone; pyrone; crystal structure