Zinc(II), cadmium(II), mercury(II) and lead(II) semiquinone-type complexes of a new schiff-base ligand: antibacterial studies

摘要

A new Schiff-base ligand LH_2, has been preparedby reaction of 2,9-diformyl-1,10-phenanthroline with 2,3-diamino-1,4-naphthoquinone. The formation and characterizationof complexes of Zn(II), Cd(II), Hg(II) and Pb(II) with the semi-oxidized ligand LH is described. The M(LH)X_2 (X=Cl, Br andAcO) radical species are paramagnetic and the observed EPRsignals in the solid state at room temperature, with g values closeto the electron free g value are proof of the semiquinonic characterof the ligand. The antibacterial activity of the ligand and the metalcomplexes prepared were tested against four bacteria strains andcompared with the activity of penicillin.