IRON(III), COBALT(II), NICKEL(II), COPPER(II) AND ZINC(II) COMPLEXES OF 4-FORMYLANTIPYRINE THIOSEMICARBAZONE

Complexes of iron(III), cobalt(II), nickel(II), copper(II) and zinc(II ) with 4-formylantipyrine thiosemicarbazone (HFoAtsc) have been prepar ed and spectrally and physically characterized. IR, electronic, and ES R spectra of the complexes, as well as IR, electronic and H-1 and C-13 NMR spectra of HFoAtsc, have been obtained. The spectral studies show that HFoAtsc behaves as neutral or monobasic bidentate ligand in all complexes except [Fe(FoAtsc)(2)]ClO4 and [Co(HFoAtsc)(2)](BF4)(2), whe re the thiosemicarbazone bonds in a monobasic tridentate fashion in th e former and a neutral tridentate manner in the latter. Coordination t akes place via the azomethine nitrogen and the thione or thiolato sulf ur for bidentate coordination and the carbonyl oxygen of the pyrazolon e ring is added for tridentate coordination.