Synthesis,characterization and antimicrobial activity of cobalt(II), nickel(II)and copper(II) complexes with new asymmetrical Schiff base ligands derived from 7-formyanil-substituted diamine-sulphoxine and acetylacetone

Asymmetric 7-formyanil-substituted-imino-4-(4-methyl-2-butanone)-8-hydroxyquinoline-5-sulphonic acid (Schiff bases), react with Co^II, Ni^II and Cu^II ions to give 1:2, 1:1 and 2:1 complexes as established by conductometric titrations in 1:1 DMF:H₂O. The complexes were investigated by elemental analyses, molecular weight determinations, molar conductance, magnetic moments, thermal analysis, i.r., u.v.–vis. and e.s.r. spectra. The complexes have an octahedral crystal structure and general formula ML·(OH₂)₂], where M^II = Co, Ni and Cu, and L = Na7—X—HL], (—X— = (CH₂)₂, (CH₂)₃, p-C₆H₄, o-C₆H₄). Antimicrobial activity of these new ligands and their transition metal complexes has been screened in vitro on common fungi and bacteria.