Asymmetrical modification of Wells-Dawson POMs by Cu-phnz coordination polymers

A new asymmetrically modifying Wells-Dawson polyoxometalates (POMs), {[Cu-3(C12N2H8)(5)] (H2P2W18O62)}center dot 0.5[Cu-2(C12N2H8)(3)]center dot(C12N2H8), have been synthesized and structurally characterized. X-ray diffraction analysis reveals that the Wells-Dawson POMs are asymmetrically functionalized by [Cu (C12N2H8)(2)] monomers and [Cu-2(C12N2H8)(3)] dimers, and the asymmetrical coordination mode to stabilize the Wells-Dawson POMs has never been found in the POM chemistry hitherto. In the crystal engineering point of view, the bigger steric hindrance, the polycyclic aromatic bridging and conjugated action of the phnz molecules facilitate the formation of asymmetrical coordination mode of the Wells-Dawson POMs. Additionally, the electrochemical behavior of the title compound modifying CPE (1-CPE) has been studied. (C) 2010 Elsevier B.V. All rights reserved.