REACTION OF COORDINATED LIGAND-IV - SYNTHESIS AND CHARACTERIZATION OFSOME LANTHANIDE COMPLEXES OF 2,6-DIACETYLPYRIDINE 2-THENOYL SALICYL DIHYDRAZONE

The complexes of the type [Ln(H(2)dapthsh)Cl(H2O2)]Cl-2 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy; H-2 dapthsh = 2, 6-diacetylpyridine 2-theno yl salicyl dihydrazone) have been prepared by reacting salicylhydrazon e (sh) with [Ln(Hdapth)Cl-2(H2O)(3)] Cl (Hdapth = 2,6-diacetylpyridine mono (2-thenoylhydrazone) in ethanol. The condensation of coordinated acetyl C=O with - NH2 of salicylhydrazone occurs and the resulting az omethine nitrogen is found bonded to the Ln(III) ions. The compound ha s been found monomeric from FAB mass spectra. The bonding sites of the dihydrazone and coordination number and symmetry of the ligand field around Ln(3+) ions have been deduced from IR, electronic and emission spectra.