Synthesis, structure and properties of eight novel molybdenum(VI) complexes of the types: [MoO2LD] and [{MoO2L}2D] (L = thiosemicarbazonato ligand, D = N-donor molecule)

Eight new molybdenum(VI) complexes with 4-(diethylamino)salicylaldehyde and 2-hydroxy3-methoxybenzaldehyde thiosemicarbazones have been prepared. They were characterized as mononuclear [MoO2LD] or dinuclear [{RMoO2L}(2)D] complexes. In all the compounds the MoO22+ core is coordinated by a tridentate ONS thiosemicarbazonato ligand and by the N-clonor molecule (imidazole, pyridine or gamma-picoline). All the complexes were characterized by chemical analysis, IR spectroscopy and thermogravimetry. Three of the mononuclear complexes, dioxo[(2-hydroxy-3-methoxybenzaldehyde thiosemicarbazonato)(pyridine)]molybdenum(VI), dioxo[(2-hydroxy-3-methoxybenzaidehyde thiosemicarbazonato)(gamma-picoline)]molybdenum(VI) and dioxo[(2-hydroxy-3-methoxybenzaldehyde thiosemicarbazonato)(imidazole)lmolybdenum(VI) were also characterized by single-crystal X-ray structural analysis. A spectrophotometric method for the determination of molybdenum based on extraction of ion-pairs formed by the cationic surfactant and the [MoO(SCN)(4)](-) anion is described. (C) 2009 Elsevier Ltd. All rights reserved.