STUDIES ON SOME BIVALENT-METAL COMPLEXES OF SCHIFF-BASES

2-Acetylfuran-2-furoylhydrazone (Haffh), 2-acetylthiophene-2-furoylhyd razone (Hatfh), o-hydroxyacetophenone-2-furoylhydrazone (H2hafh) and 2 ,6-diacetylpuridine bis(2-furoylhydrazone) (H2dapfh) react with zinc(I I), cadmium(II) and mercury(II) chlorides and form the complexes of th e types ML2Cl2 [M = Cd(II) and Hg(II), L = Haffh and Hatfh; M = Zn(II) , Cd(II) and Hg(II), L = H2hafh], [MLCl]Cl [M = Cd(II) and Hg(II) and L = H2dapfh] and Zn(Hhafh)2. The complexes M(H2acacfh)Cl2 [M = Cd(II) and Hg(II), H2acacfh = acetylacetonebis(2-furoylhydrazone)] were prepa red by template reaction. The complexes were characterized by elementa l analyses and molar conductance. Infrared spectral studies reveal neu tral bidentate bonding of Haffh, Hatfh and H2hafh in the complexes, ex cept Zn(Hhafh)2, in which the Schiff base is bonded in an uninegative tridentate fashion. H2dapfh is a neutral pentadentate ligand while H2a cacfh is neutral tetradentate ligand. These observations are also supp orted by H-1 and C-13 n.m.r. spectral studies. A six-coordinate geomet ry around the metal ions has been proposed on the basis of these studi es.