SYNTHESIS, CHARACTERIZATION, EQUILIBRIUM AND BIOLOGICAL STUDIES OF NOVEL 33-(1-(BENZO[D]THIAZOL-2-YLIMINO)ETHYL)-6-METHYL-2H-PYRAN-2,4(3H)-DIONE AND ITS Cu (II), Ni (II) AND Hg (II)METAL COMPLEXES: AN EXPERIMENTAL AND THEORETICAL APPROACH

The compound 3-(1-(benzo[d]thiazol-2-ylimino) ethyl)-6-methyl-2H-pyran-2, 4(3H)-dione (3BTIEMPD) and its metal complexes were prepared and characterized by spectro-analytical techniques. Irving-Rossetti pH-metric technique was employed to determine the number of dissociable protons and chelation sites of the title compound. Hyper Chem 7.5 software was used to understand donor and acceptor properties of molecule. The molecule was built and the geometry optimization was carried out by using semiemperical PM3 method.  The contour maps of highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) and corresponding binding energy values were computed. The low binding energy for ionic species evident from computed values is an indication of higher possibility of compound to bind with metal ions through deprotonation. This is augmented from the results of spectro-analytical analyses of isolated solid metal complexes wherein   the participation of azomethine nitrogen and the enol oxygen of pyran ring through deprotonation is envisaged. All the compounds were investigated for their antimicrobial activities against the Gram-positive and Gram-negative bacteria by disc diffusion method. It was found that the antibacterial activity of Hg (II)-3BTIEMPD is dominant over standard ampicillin