Microwave assisted synthesis, spectral characterization and biological activities of zn(ii) complex with n,n -donor and octanoate ion as ligands

A novel Zn(II) complex of 2-aminobenzonitrile(ABN)  and   octanoate(OC)  ion was synthesized by using microwave irradiation. Microwave synthesis gives high yield of the complex within a short time. The molecular formula and the probable geometry of the complex have been deduced from elemental analysis, molar conductance, UV, FT-IR, and NMR spectra. The molar conductance indicates that the Zn(II) complex is a non-electrolyte. FT-IR spectra show that 2-aminobenzonitrile is coordinated to the metal ion in a bidentate(N,N-donor) and octanoate ion in monodentate manner. The nature of bonding in this diamagnetic complex was arrived from NMR spectra.  The geometry of the complex is found to be tetrahedral. The antimicrobial activities of ligands and their Zn(II) complex were studied against the two Gram +ve bacteria (staphylococcus aureus, streptococcus), and five Gram –ve bacteria (klebsilla, pseudomonas aeruginosa, salmonella typhi, Enterobacter, E.coli) and also three fungi (C.albicance, Aspergillus Flavus and Aspergillus Niger ) at different concentrations by agar- well diffusion method.  The complex shows enhanced activity against the bacteria and moderate activity against the fungi compared to the free ligands. The free radical scavenging activity of metal complexes have been determined by measuring their interaction with the stable free radical DPPH and the compounds have shown encouraging antioxidant activities.