Studies on biologically active complexes of Co(II), Ni(II) & Cu(II) with benzimidazole oximes

Abstract

Thirteen ne non-ionic and paramagnetic complexes of Co(II), Ni(II) and CU(II) of stoichiometries M(LH₂)X₂.2H₂O (M = Ni and Cu; X = Cl^-); M(LH₂).Y₂.2H₂O (M = Cu; Y = NO<img src='/image/spc_char/3_bar.gif' border=0>; 1/2SO<img src='http://www.niscair.res.in/jinfo/four1.gif' border=0>); M(LH).X.nH₂O (M = Co, n = O; M = Ni and Cu, n = 3; X = Cl); M(L).nH₂O (M = Ni, n = 3; M = Cu, n = 1); and M(LH)₂.2H₂O (M = Co and Ni) where LH₂ = 2-acetyl- or 2-benzoyl-benzimidazole oxime, have been synthesized and characterised. In the present complexes the oxime ligands exhibit five different coordination modes using different combinations of oximino nitrogen, pyrrole nitrogen and pyridine nitrogen as donor atoms. The complexes have been characterised on the basis of their magnetic and spectral properties and thermal studies. In majority of the cases the antibacterial and antifungal activities substantially increase on complexation of the oximes with metals.