Studies and Synthesis of Biologically Active Mixed Ligand Cerium (III) Complexes

Mixed ligand complexes cerium (III) of the type [M (Q) (L) 2H2O] have been synthesized by using 8-hydroxy quinoline (HQ) as a primary ligand and N- and/or O- donor amino acids (HL) such as L-proline, L-valine and L-serine as secondary ligands. The metal complexes have been characterized by elemental analysis, electrical conductance, room temperature magnetic susceptibility measurements, spectral and thermal studies. The electrical conductance studies of the complexes indicate their non-electrolytic nature. Room temperature magnetic susceptibility measurements specify that cerium (III) complexes are paramagnetic in nature. Electronic absorption spectra of the complexes show intra-ligand, charge transfer and d-d transitions respectively. The thermal analysis data of the complexes indicates the presence of coordinated water molecules. FTIR spectra show bonding of the metal ion through N- and O- donor atoms of the ligand molecules. Tube dilution and Agar cup methods were implemented for study of antibacterial activity of the complexes against S. aureus, C. diphtheriae, S. typhi and P. aeruginosa. The tetracycline is used as standard antibacterial compound to study the antibacterial study of the synthesized complexes and it was found that, the complexes show mild activity against selected strains of micro-organisms as compared to standard tetracycline.