ChemInform Abstract: Coordination and Valence of Europium in the Heteropolyanion ( EuP5W30O110)12‐.

Abstract

1995 structure structure (solids and liquids) D 2000 -006Coordination and Valence of Europium in the Heteropolyanion ( EuP5W30O110)12-.-The Eu-encrypted title anion, prepared by Eu3+ exchange reaction of K12.5Na1.5(NaP5W30O110) ·15 H2O, is characterized by XANES data, high-resolution excitation and emission spectra in the solid state at liquid He temperature, and 31P-NMR spectra. According to the XANES data and confirmed by the optical spectra, Eu is trivalent in the anion. The time delayed optical fluorescence spectra show the presence of two structurally inequivalent Eu ions inside the heteropoly cavity. The different Eu sites, which are not occupied in the same anion, exhibit different life times. The difference can be attributed to a different number of water molecules coordinating to Eu. Samples with either one or two Eu sites occupied are indistinguishable in the cyclic voltammogram and the 31P-NMR spectra. -(SODERHOLM, L.; LIU, G. K.; MUNTEAN, J.; MALINSKY, J.; ANTONIO, M. R.; J. Phys. Chem. 99 (1995) 23, 9611-9616; Chem. Div., ANL, Argonne, IL 60439, USA; EN)