Circular Dichroism Studies of Metal Complexes of Chiral Schiff Base Ligands

摘要

A number of monometallic complexes of a new optically active Schiff base i.e., R-1,2-propane-bis-(5-imino-1-phenyl-1,3-hexadione) (R-pn(HBAA)2)) have been synthesized and characterized by their elemental analysis, infrared and absorption spectra. These complexes have general formula (M(R-pn(BAA)2))S,(M=VO(2+),Fe(2+),Co(2+),Ni(2+), Cu(2+) and Uo2(2+) and S = H2O or C3H6O). The Fe(2+), Co(2+), Ni(2+) and Cu(2+) complexes are four coordinated, square planar while five coordinated (VO(R-pn(BAA)2)) has a square pyramidal and seven coordinated (UO2(R-pn(BAA)2).C3H6O) has a pentagonal bipyramidal structure. The CD spectra of these complexes in acetonitrile, chloroform and dioxane are reported. Cotton bands are assigned to electronic excitations in various complexes. These complexes show strong inhibitory effects against a number of gram negative bacteria such as E.Coli, K.Pneumoniae, P.Miralulis, P.Aeruginosa, C.Freundii and S.Typhi and a gram positive bacteria S.Aureus. The ligands show very little antibacterial activity against all of these bacteria.