Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+ Complexes of Butanedione Hydrazones: Spectroscopic, Thermal and Biological Studies

Abstract

Complexes of Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+ with malonyl- and succinoyl bis(2,3-butanedionehydrazone) [MBH, SBH] have been synthesized and characterized. Single crystal of SBH was found monoclinic with space group of P121/c14. The MBH complexes have the formulae: [Co(MBH)Cl2].H2O, [Ni(MBH-2H)(H2O)2].2H2O, [Cu(MBH-2H)(H2O)2].2H2O, [Cu(MBH-H)(OAc)].2H2O while the SBH complexes have [Co(SBH-H)(H2O)], [Ni(SBH-H)2], [Ni(SBH)Cl2], [Cu(SBH-H)Cl], [Cu(SBH-H)(OAc)].2H2O, [Zn(SBH)2Cl]Cl, [Cd(SBH-H)2].-H2O and [Hg2(SBH)2Cl2]Cl2. All complexes are nonelectrolytes except [Zn(SBH)2Cl]Cl and [Hg2(SBH)2Cl2]Cl2.5H2O. MBH and SBH ligate as neutral, mononegative and/or binegative bidentate. The carbonyl group (C=O)ketone is not taking part in complexation. The magnetic moments and electronic spectra afford a tetrahedral geometry for the Zn2+ and Cd2+ complexes; square-planar for the Co2+ and [Ni(SBH)Cl2] complexes and octahedral for the other complexes. The thermal decomposition of the complexes revealed the outer and inner solvents as well as the remaining part which is metal or metal oxide in some cases. The complexes have variable activities against some bacteria and fungi. [Hg2(SBH)Cl2] Cl2.5H2O has the highest activity against all tested organisms. [Ni(SBH-H)2] and [Zn(SBH)2]Cl2 hve activity against Bacillus and E. coli. On the other hand, MBH and [Co(MBH)Cl2].H2O have activity against Penicillium only.