In vitro antibacterial activity of meclofenamate metal complexes with Cd(II), Pb(II), Co(II), and Cu(II). Crystal structures of [Cd(C_(14)H_(10)NO_2Cl_2)_2?(CH_3OH)]_n and [Cu(C_(14)H_(10)NO_2Cl_2)_2(C_5H_5N)_2]

摘要

The synthesis and characterization of five metal complexes derived from sodium meclofenamate (1) are reported: [Cd(C_(14)H_(10)NO_2Cl_2)_2?(CH_3OH)]_n?nCH_3OH (6), [Pb(C_(14)H_(10)NO_2Cl_2)2]_n (7), [Co(C_(14)H_(10)NO_2Cl_2)]_n (8), [Cu(C_(14)H_(10)NO_2Cl_2)]_n (9), and [Cu(C_(14)H_(10)NO_2Cl_2)_2(C_5H_5N)_2] (10) (C_(14)H_(10)NO_2Cl_2 = meclofenamate; C_5H_5N= pyridine). The characterization of the compounds was based on FTIR and UV-visible spectroscopy, mass spectrometry and, in the case of complexes 6 and 10, single crystal X-ray diffraction analysis. For compound 6, the structural analysis revealed a 1-D polymeric chain structure, in which pentagonal planar [Cd(RCOO)_2(CH_3OH)] unitswere linked through bridging carboxylate functions of themeclofenamate ligands. The overall coordination environment of the Cd(II) ionswas seven-coordinate, since each carboxylate group exhibited a μ_3-bridging coordination mode. On the other hand, for complex 10 a discrete mononuclear structure was observed, in which the six-coordinate copper(II) metal atoms were coordinated by two pyridine molecules and the carboxylate functions of two meclofenamate entities, in an anisobidentate coordination mode. The antibacterial activity of compounds 6-9 against four strains of Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria was examined, finding that only complex 6 was active. Additionally, it was found that the Co(II) and Cu(II) complexes 8 and 9 showed peroxidase activity.