SYNTHESIS, CHARACTERIZATION AND THERMAL INVESTIGATION OF SOME METAL-COMPLEXES DERIVED FROM NEW SCHIFF-BASE LIGANDS

A new series of complexes of palladium(ll), oxovanadium(IV) and zinc(I I) ions with N-(3,4-dihydroxy salicylidene)-3,5 -di(tert-butyl)-4-hydr oxyaniline(HL) and N-(4,6-dihydroxy- salicylidene-3,5-di(tert-butyl)-4 -hydroxyaniline (HL1) have been prepared and characterized by elementa l analyses, electronic absorption spectral data, infrared, magnetic mo ment and molar conductance data. In order to determine the structures of the ligands with their palladium(ll) and zinc(il) complexes,H-1 and C-13 NMR spectra were obtained. All compounds were found to be non-el ectrolytes in DMSO (similar to 1 mM). The thermal behaviour of the lig ands and their complexes have been investigated using thermogravimetri c techniques (TG and DTA). The thermogravimetric data agree with the r esults of the analytical and spectral analyses. The degradation of the hydrated complexes occurs in several steps with the dehydration react ion followed by complete decomposition to the corresponding metal oxid es.