LIGATIONAL BEHAVIOR OF 2 BIOLOGICALLY-ACTIVE N-S DONORS TOWARDS COBALT(III), IRON(III), IRON(II) AND RHODIUM(III)

The chelating behaviour of two biologically active ligands, pyridine-2-carboxaldehyde(4-phenyl) thiosemicarbazone(L1H) and pyridine-2-carboxaldehyde thiosemicarbazone(LH), towards FeIII, CoIII, FeII and RhIII has been investigated. The ligands act as tridentate N-N-S donors, resulting in the formation of bis-chelate complexes of the type MIII(A)2X·nH2O (A=L1 or L; X=Cl, ClO4; M=CoIII, RhIII, FeIII), FeII(L1H)2SO4·2H2O and FeII(L1)2·H2O. Biological activity of the ligands and the metal complexes in the form of in vitro antibacterial activities towards E. coli has been evaluated and the possible reasons for enhancement of the activity of ligands on coordination to metal ion is discussed. © 1990 Chapman and Hall Ltd.