6533b7d3fe1ef96bd1260bef

RESEARCH PRODUCT

Cinoxacin complexes with divalent metal ions. Spectroscopic characterization. Crystal structure of a new dinuclear Cd(II) complex having two chelate-bridging carboxylate groups. Antibacterial studies.

subject

description

Several cinoxacin (HCx) complexes with divalent metal ions have been prepared and characterized by spectroscopic techniques. The crystal structure of [Cd 2 (Cx) 4 (H 2 O) 2 ] · 10H 2 O has been determined by X-ray diffraction. The complex is triclinic, space group with unit-cell dimensions: a =10.412(2), b =11.119(2), c =13.143(6)A, α=76.78(4)°, β =74.59(3)°, γ =77.12(3)°, V =1406.0(8) A 3 . In this complex each cadmium atom is heptacoordinated; the metal environment is formed by two O keto and two O carbox atoms from two different cinoxacinate monoanions, two carboxylate oxygen atoms from a third cinoxacinate ligand and by one water oxygen atom on the seventh position. Two of the cinoxacinate ions act as tridentate chelate and bridging ligands and the other one as a bidentate chelate ligand. In the bridging monoanions the carboxylate group is behaving as a chelate ligand. All the complexes were screened for their activity against several bacteria, showing activity similar to that of cinoxacin. Additionally, the number of bacteria killed after 3 h of incubation with cinoxacin, [Cu(Cx) 2 ] · 2H 2 O and [Co(Cx) 3 ]Na · 10H 2 O complexes was determined against E. coli ATCC 25922; the copper compound presents paradoxical effect which has been described and related to the mechanism of action of quinolones.