Synthesis and X-ray structural analysis of complex formation with chalcogensemicarbazones of 8-quinolinecarboxaldehyde

Abstract

Three new complexes of cobalt with chalcogensemicarbazones of 8-quinolinecarboxaldehyde were synthesized and characterized by X-ray analysis, elemental analysis, NMR, IR spectroscopy and molar conductivity and magnetic moment measurements. The aim of this study was to understand the ways of coordination chalcogensemicarbazones to the metal ion. The complexes have the following formulas: [Co (H8qasc) 2] Cl2 · 2H2O (1), [Co (8qatsc) 2] ClO4 · DMSO (2), [Co (8qasesc) 2] ClO4 · DMSO (3). All three complexes are prepared by the condensation reaction of 8-quinolinecarboxaldehyde with suitable chalcogensemicarbazones in a solution of ethanol and recrystallization of the product from the methanol in complex 1, while in the complex, 2 and 3, the product recrystallized ethanol vapor diffusion method in DMSO to a solution of the crude product. As products of the recrystallization of the resulting crystals of the complex. The geometry of all three complexes is octahedral, where ligands are coordinated to a tridentately via the quinoline and imine nitrogen atoms and chalcogen atoms where in each of them with a metal ion being forming according to a five-membered and a six-membered ring. In the complex 1 Two ligands in neutral form are coordinated to Co(II) ion, outside the sphere constructed of two chloride anions and two molecules of water. In the complex 2 and 3, the two corresponding ligands are coordinated in monoanionic form, perchlorate anion and molecules DMSO are situated in the outer sphere of the complex. All the complexes showed significantly higher antimicrobial and cytotoxic activity compering to the ligands. Keywords: cobalt, chalcogensemicarbazones X-ray, single crystals, antimicrobial.