Synthesis and spectral characterization of naphthyldihydrazones derived from some 1,3- dicarbonyl compounds and their Ni(II), Cu(II) and Zn(II) complexes

The coupling of tetrazotised 1,8-diaminonaphthalene with 1,3-dicarbonyl compounds [acetylacetone, methylacetoacetate and acetoacetanilide] yielded a new series of tetradentate ligand systems. Analytical, IR, 1H NMR and mass spectral data indicate that the compounds exist in the intramolecularly hydrogen bonded dihydrazone form. Dibasic tetradentate N2O2 coordination of these compounds in their [ML] complexes [M = Ni(II), Cu(II) and Zn(II)] has been established on the basis of analytical and spectral data. The Ni(II) and Zn(II) chelates are diamagnetic while Cu(II) complexes showed normal paramagnetic moment.