Synthesis, structures and oxygen atom transfer catalysis of oxo-bridged molybdenum(V) complexes with heterocyclic bidentate ligands (N,X) X = S, Se

Abstract

The dinuclear μ-oxomolybdenum(V) complexes [Mo 2O 3(PyS) 4] ( 1), [Mo 2O 3(PySe) 4] ( 2) and [Mo 2O 3(4-CF 3-PymS) 4] ( 3) were obtained by similar reactions of the [MoO 2Cl 2(DME)] precursor with the corresponding heterocyclic bidentate (N,X) ligands, X = S, Se, where PyS, PySe and 4-CF 3-PymS are the anions of pyridine-2-thione, pyridine-2-selenolato and 4-trifluoromethyl-2-pyrimidinthiol, respectively. All compounds were characterized by elemental analysis, IR, NMR, EI-MS spectroscopy and X-ray diffraction. The crystal structures of 1– 3 all include the common [Mo 2O 3] 4+ core. Compounds 1 and 2 are isostructural. The catalytic oxo-transfer properties of the molybdenum(V) compounds 1 and 2 were studied by the use of PPh 3 in DMSO with a considerably higher catalytic activity for the thionato containing complex 1 than for its selenolato containing analogue 2.