Original Articles
Syamal Adhikari, Ram A Lal, Al
Abstract
The mononuclear manganese(IV) complexes of the composition [Mn(sloh)(D)2].2H2O(H4sloh= disalicylaldehyde oxaloyldihydrazone) (D= H2O(1), py(2), 2-pic(3),3-pic(4), 4-pic(5)) and K[Mn(sloh)F(H2O)]. 2H2O have been synthesized in ethanol from manganese(II) acetate, oxaloyldihydrazine and salicylaldehyde directly by the template method and characterized by various physico-chemical and spectroscopic techniques. The stoichiometry of the complexes has been established based on elemental analyses, thermoanalytical, molecular weight and molar conductance data. The structural assessment of the complexes has been carried out on the basis of magnetic moment, electronic, IR and ESR spectral data. All of the complexes except complex 6 are nonelectrolytes. The μeff values suggest that in all of the complexes manganese is present in +4 oxidation state. The electronic spectra of the complexes are dominated by strong charge transfer bands. In all of the complexes, the dihydrazone coordinates to the manganese centre as a tetrabasic tetradentate ligand in keto form in the anti-cis-configuration.The complexes are suggested to have six-coordinate octahedral stereochemistry around the manganese centre.