Study on ligation of copper complexes of the quinolone antibacterial drugs and octamolybdates POMs

By introducing different quinolone antibacterial drugs into the octamolybdates POMs, four new compounds, [Cu-II(L-I)(2)(H2O)(2)]H-2[beta-Mo8O26]center dot 4H(2)O (1), [Cu-2(II)(L-2)(4)][delta-Mo8O26]center dot 4H(2)O (2), [Cu-2(II)(L-3)(2)(H2O)(2)] [beta-Mo8O26] (3), [Cu-2(II)(L-4)(2)(H2O)(4)][beta-Mo8O26]center dot 2H(2)O (4) (where L-1 = Enrofloxacin; L-2 = Pipemidic Acid; L-3 = Norfloxacin: L-4 = Enoxacin), have been synthesized and characterized by routine physical methods and single crystal X-ray diffraction. In compound 1, isolated Cu-Enrofloxacin coordination subunits array the both sides of beta-Mo8O26, forming 3D supramolecular structure via noncovalent interactions. And the Cu-Pipemidic Acid subunits covalently link delta-Mo8O26 to form 3D supramolecular structures via short interactions in 2. In 3, the Cu-Norfloxacin motif exhibits 1D chain structure, and the tetra-dentate beta-[Mo8O26](4-) clusters interact with neighboring chains to construct a 2D sheet. Similar to that of 3, the Cu-Enoxacin subunit in 4 exhibits 1D chain structure, and the bi-dentate beta-[Mo8O26](4-) clusters interact with neighboring chains to construct a 2D sheet. Due to the introduction of different drug molecules, the octamolybdates POMs exhibit different isomers and structures, which bring different properties. The antitumor activities of compounds 1-4 in vitro were studied by MTT experiments, and the results show that introduction of different drug molecules onto the polyoxoanion surface can affect their antitumor activities. (C) 2011 Elsevier Ltd. All rights reserved.