Synthesis and physico-chemical characterization of chelates derived from 2-hydroxy-5-methylacetophenone-S-benzyldithiocarbazate

Chelates of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), VO(IV) and UO2( VI) with Schiff base ligand derived from 2-hydroxy-5-methylacetophenone and S-benzyldithiocarbazate have been synthesized. They have been characterize d by elemental analysis, IR, reflectance spectra, magnetic susceptibility, molar conductance, molecular weight and thermal studies. The stoichiometrie s of the chelates are represented as MnL . 2H(2)O, CoL . 2H(2)O, FeL . 3H(2 )O, NiL . 3H(2)O, CuL, ZnL . H2O, VOL . H2O and UO2L . H2O (where L = Schif f base). The copper(II) and VO(IV) chelates exhibit a subnormal magnetic mo ment due to antiferromagnetic exchange interaction, while the Mn(II), Fe(II ), Co(II) and Ni(II) complexes exhibit normal magnetic moments at room temp erature. IR and H-1 NMR spectral studies show that the Schiff base behaves as a dibasic and tridentate ligand coordinating through the deprotonated ph enolic oxygen, azomethine nitrogen and thioenolic sulphur. The thermogravim etric data have been analyzed for kinetic parameters using Freeman-Carroll and Sharp-Wentworth methods.