Synthesis, characterization, crystal structure, in-vitro cytotoxicity, antibacterial, and antifungal activities of nickel(II) and cobalt(III) complexes with acylthioureas

Abstract

Two thiourea derivatives 1-pentanoyl-3-methyl-3-(4-chlorophenyl)thiourea (HL1) and 1-(3-fluorobenzoyl)-3,3-diphenyl-thiourea (HL2) and their nickel(II) (1) and cobalt(III) (2) complexes have been prepared. The synthesized compounds have been adequately characterized by spectroscopic techniques including elemental analyses, FT-IR, 1H and 13C NMR, and single crystal diffraction. The FT-IR and 1H NMR studies of complexes reveal the occurrence of ligands in the deprotonated states which are coordinated to metal ions in a bidentate fashion. Moreover, this deprotonation brings carbonyl group to contribute to electronic delocalization in the frame –C(O)NC(S)–. Complexes 1 and 2 are crystallized in monoclinic C2/c and triclinic P-1 space groups, respectively. In-vitro bioactivities of synthesized compounds such as brine shrimp lethality assay, antibacterial screening against Enterobacter aerogenes, Bordetella bronchiseptaca and Salmonella typhimurium strains, and antifungal investigation versus Fusarium solani, Aspergillus fumigatus and Mucor fungal strains have also been evaluated. In general, the antibacterial activities of tested compounds are found significantly higher as compared to their antifungal inhibition and cytotoxic activities.