title: Spectral, thermal and in vitro antimicrobial studies of cyclohexylamine-N-dithiocarbamate transition metal complexes.
abstract: Transition metal complexes of the type [M(L)(2)] and those containing monodentate phosphines of the type [M(L)(2)(PPh(3))] {M=Ni, Co, Cu and Zn; L=cyclohexylamine-N-dithiocarbamate; PPh(3)=triphenylphosphine} have been synthesized. The complexes were characterized using IR, UV-vis, NMR spectroscopy, and thermal analysis (TGA). The (1)H NMR, (13)C NMR and (31)P NMR showed the expected signals for the dithiocarbamate and triphenylphosphine moieties. The spectral studies in all compounds revealed that the coordination of metals occurs via the sulphur atom of the dithiocarbamate ligand in a bidentate fashion. Thermal behavior of the complexes showed that the complexes were more stable than their parent ligands. The ligand moiety is lost in the first step and the rest of the organic moiety decomposes in the subsequent steps. Furthermore, the ligand and their metal complexes were screened in vitro for their antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Enterococcus faecalis, Pseudomonas aeruginosa and Bacillus cereus and antifungal activities against Aspergillus flavus, Aspergillus carbonarius, Aspergillus niger and Aspergillus fumigatus. The metal complexes exhibited higher antimicrobial activity than the parent ligands. Generally, the zinc complexes were effective against the growth of bacteria with Zn(L)(2) displaying broad spectrum bacteriocidal activity at concentrations of 50microg/mL; and Ni(L)(2) was more effective against the growth of fungi at concentrations of 100-400microg/mL under laboratory conditions.
authors.affiliation: Department of Chemical Technology, University of Johannesburg, Johannesburg, Gauteng, Doornfontein, South Africa.
authors.forename: Saul M
authors.initials: SM
authors.lastname: Mamba
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Mishra
authors.forename: Bhekie B
authors.initials: BB
authors.lastname: Mamba
authors.forename: Patrik B
authors.initials: PB
authors.lastname: Njobeh
authors.forename: Mike F
authors.initials: MF
authors.lastname: Dutton
authors.forename: Elvis
authors.initials: E
authors.lastname: Fosso-Kankeu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology; D001230:Aspergillus / Q000187:drug effects; D056831:Coordination Complexes / Q000737:chemistry*; D052978:Disk Diffusion Antimicrobial Tests; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests / Q000379:methods; D010720:Phosphines / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013818:Thermogravimetry; D013859:Thiocarbamates / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D056831:Coordination Complexes; D010720:Phosphines; D013859:Thiocarbamates; D028561:Transition Elements; C011209:cyclohexyldithiocarbamate