Antibacterial and DFT Computational Studies of a Novel Schiff Base Ligand derived from the Chiral Amino acid S- Carboxy Methyl-L-Cysteine and its Transition Metal Complexes

Antibacterial and DFT studies of a novel chiral Schiff base ligand S-Carboxy Methyl-L- Cysteine and 5- bromoisatin (CMCBI) derived by the condensation of the chiral amino acid CMCBI in basic medium and its Co(II), Ni(II), Cu(II), Zn(II), complexes have been reported in this study. The elemental analysis, FTIR, H1 NMR and UV-visible spectral data suggest the formation of the Schiff base ligand CMCBI and M(CMCBI)2 type metal complexes. Cu (II) and Co (II) complexes show marked biocidal activities against different microbes. The geometrical and electrical characteristics of the experimental data are compared with theoretical data obtained from the Density Functional Theory (DFT) calculations using Gaussian 09. Electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), ionization potential (IP), electron affinity (EA), hardness (g), softness (S) and electronegativity (ϖ) are determined theoretically. Cu (II), Co (II) and Zn (II) complexes show promising activities against different bacterial strains such as Bacillus, Staphylococcus and Proteus.