Synthesis and characterisation of two new lanthanide sandwich-type heteropolyoxometalates

Abstract

The sodium and cesium salts of two new heteropolyoxometalate complexes [{Ln3O3(OH2)2}(PW9O34)2] 15 were synthesized and studied using spectroscopy and cyclic voltammetry. The stoichiometry of the trilacunary Keggin 9-tungstophosphate reaction with Ln(III) ions was determined with the aid of conductometric titrations of aqueous solutions. Ion-exchange as well as ES-MS experiments provided evidence for covalent, inner-sphere bonding of lanthanide cations to the trilacunary a-[PW9O34] heteropolyanion. Cyclic voltammograms of [{Ln3O3(OH2)2}(PW9O34)2] 15 exhibited two pairs of reduction/oxidation waves with negative half-wave potential (E1/2) values. These waves were attributed to redox processes corresponding to the polyoxotungstate framework. The redox processes of the Ce derivative revealed the presence of two types of cerium ions. # 2003 Elsevier Ltd. All rights reserved.

Cite this paper

@inproceedings{Tomsa2003SynthesisAC, title={Synthesis and characterisation of two new lanthanide sandwich-type heteropolyoxometalates}, author={Adrian-Raul Tomsa and Liana Maria Muresan and Aglaia Koutsodimou and Polycarpos Falaras and Mariana Rusu and Paraskevi Attikis}, year={2003} }