Synthesis and Characterization of Molybdenum and Tungsten Complexes of N-Nicotinoyl-N'-2-Thiophenethiocarbohydrazide

Molybdenum and tungsten complexes of the type M₂O₄L₂(H₂O)₂, where M = Mo(V), W(V), LH = N-nicotinoyl-N'-2- thiophenethiocarbohydrazide (H₂NTTH), have been synthesized and characterized by using elemental analysis, magnetic susceptibility measurements, infrared spectra, ¹HNMR, ¹³CNMR,ESR.and X-ray spectroscopic studies. Molar conductance measurements in DMF show non-ionic behaviour of all the complexes. Magnetic susceptibility measurements indicate diamagnetic nature of the complexes. Although the complexes are ESR inactive, +V oxidation state of metal ions in octahedral geometry has been suggested on the basis of electronic spectral studies. IR and electronic spectral studies indicate dinuclear - type of complexes with M₂O₄ ²⁺ moiety. IR spectral data suggest monoanionic bidentate mode of bonding for the ligand. The ¹H NMR and ¹³C NMR spectra are found to be in good agreement with the proposed stoichiometry. X-ray powder diffraction of the complexes exhibit amorphous nature of the complexes.