Synthesis, Physico-Chemical Studies and Biological Activity of Glyoxalmonoisonicotinoyl Hydrazone Complexes with Some Bivalent Transition Metal Ions and Oxdcations

Complexes of the type MLX2 where M = Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Cd(II), Hg(II), VO(IV), ZrO(IV) and UO2(VI), L = glyoxalmonoisonicotinoyl hydra zone, X = Cl, NO3 and ½ SO4 have been synthesized and characterized by elemental analyses, physico-chemical and solid state conductance studies. The complexes are stable and insoluble except in DMF, DMSO and decompose above 200°C without melting. The Cu(II), Ni(II), Co(II) and Mn(II) complexes are paramagnetic, have distorted octahedral stereochemistry and show semiconducting properties in the solid state. The ligand bonds to the metal ions through groups. The Cu(II), Ni(II), Co(II), Zn(II), Cd(II) and Hg(II) complexes were screened against Synechococcus elongatus, a nitrogen fixing blue green algae, showing a significant inhibition of growth, protein and chlorophyll synthesis in contrast to the ligand. The inhibition varies with the metal ion in the order Hg > Cd > Co > Ni > Zn > Cu in algal growth and Hg > Cd > Co > Zn > Ni ∼ Cu in protein synthesis and Hg > Cd > Co∼Ni∼Cu in chlorophyll synthesis.