Dioxomolybdenum(VI) Complexes of ONN-Chelating Thiosemicarbazones: Crystallographic and Spectroscopic (UV, IR and NMR) Studies

Abstract

Four new cis-dioxomolybdenum(VI) complexes of the closed formula [MoO2(L)CH3OH]have been obtained by the condensation of bis(acetylacetonato)dioxomolybdenum(VI) with Sallyl/propyl thiosemicarbazones in methanol. The compounds were identified with elementalanalysis, and molecular characterization by UV-Vis, FT-IR, 1H-NMR and 13C-NMR spectroscopies.Also, crystal structures of 1 and 2 were resolved by X-ray diffraction analysis. The single crystalstudies indicated a distorted octahedral geometry for complexes. It was noticed that 1 crystallizedin the monoclinic P21/c space group with Z=4, while 2 crystallized in tricilinic P-1 space group withZ=2. The O=Mo=O angles of 105.68(8)° (for 1) and 105.96(7)° (for 2) indicated the cisdioxomolybdenum structure. The spectroscopic and crystallographic studies show that thethiosemicarbazone ligands are bound to cis-MoO22+ moiety as ONN tridentate agent and the 6thcoordinated position of the molybdenum is located by the methanol molecule.