A series of three bioactive thiourea (carboxamide) derivatives, N-(dipropylcarbamothioyl)-thiophene-2-carboxamide (L(1)), N-(dipropylcarbamothioyl)-5-methylthiophene-2-carboxamide (L(2)) and 5-bromo-N-(dipropylcarbamothioyl)furan-2-carboxamide (L(3)) and their cobalt(II), copper(II), nickel(II) and zinc(II) complexes (1)-(12) have been synthesized and characterized by their IR,(1)H-NMR spectroscopy, mass spectrometry and elemental analysis data. The Crystal structure of one of the ligand, N-(dipropylcarbamothioyl)thiophene-2-carboxamide (L(1)) and its nickel(II) and copper(II) complexes were determined from single crystal X-ray diffraction data. All the ligands and metal(II) complexes have been subjected to in vitro antibacterial and antifungal activity against six bacterial species (Escherichia coli. Shigella flexneri. Pseudomonas aeruginosa. Salmonella typhi. Staphylococcus aureus and Bacillus subtilis) and for antifungal activity against six fungal strains (Trichophyton longifusus. Candida albicans. Aspergillus flavus. Microsporum canis. Fusarium solani and Candida glabrata). The in vitro antibacterial and antifungal bioactivity data showed the metal(II) complexes to be more potent than the parent ligands against one or more bacterial and fungal strains.
Keywords: Antibacterial; antifungal; carboxamides; crystal structures; metal(II) complexes.