Synthesis, crystal structure and biological activity of 1-(1H-benzoimidazol-2-yl)-ethanone thiosemicarbazone and its cobalt complex


POYRAZ M., SARI M., DEMİRCİ F., Kosar M., DEMİRAYAK Ş., BÜYÜKGÜNGÖR O.

POLYHEDRON, vol.27, pp.2091-2096, 2008 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 27
  • Publication Date: 2008
  • Doi Number: 10.1016/j.poly.2008.03.030
  • Journal Name: POLYHEDRON
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.2091-2096
  • Keywords: ethanone, benzimidazole, thiosemicarbazone, crystal structure, antimicrobial activity, free radical scavenging activity, TRANSITION-METAL COMPLEXES, ANTIMICROBIAL ACTIVITY, 2-PYRIDINEFORMAMIDE N(4)-METHYLTHIOSEMICARBAZONE, SPECTROSCOPIC CHARACTERIZATION, NICKEL(II) COMPLEXES, MOLECULAR-STRUCTURES, COORDINATING AGENTS, FREE LIGAND, DERIVATIVES, IMIDAZOLE-2-CARBALDEHYDE

Abstract

1-(1H-Benzoimidazol-2-yl)-ethanone thiosemicarbazone (H2L) (1) was obtained by the condensation reaction of 2-acetylbenzimidazole, thiosemicarbazide and acetic acid in ethanol. The novel cobalt(III) complex [Co(L)(HL)] 2 was prepared by the direct reaction of CoCl2 center dot 6H(2)O with the ligand H2L. The reaction products were characterized by elemental analysis, thermogravimetric analysis (TGA), FT-IR and mass spectrometry for H2L, and magnetic measurement for the Co(III) complex. The crystal and molecular structures of complex 2 and the free ligand 1 were also determined by single-crystal X-ray structure analysis. The crystal structure data suggests that in compound 2, two ligands (H2L) coordinate to cobalt in a N2S tridentate fashion, giving a distorted octahedral geometry. Furthermore, compounds 1 and 2 were evaluated for their antimicrobial properties using a broth microdilution assay against various human pathogenic bacteria and the yeast Candida tropicalis, resulting in moderate minimum inhibitory concentrations (MIC = 0.25-1 mg/mL) when compared to standard antimicrobial agents. The free radical scavenging activity of the compounds against 1,1-diphenyl-2-picrylhydrazyl hydrate (DPPH) was also investigated. (C) 2008 Elsevier Ltd. All rights reserved.