Applications of spectroscopic methods in studies of polyoxometalates and their complexes with lanthanide(III) ions

Polyoxometalates (POMs), due to their attractive physical and chemical prop erties, biological significance as well as wide applications, have been the subject of numerous studies. The results of investigations concerning the synthesis, properties and structure of POMs and their lanthanide(III) compl exes (LnPOM) are briefly reviewed. Useful techniques for the verification o f POM compositions and the determination of components, including new spect rophotometric methods for the determination of tungsten and molybdenum and for simultaneous determination of these elements in structures of POMs and their LnPOM complexes, are described. The important role of the Nd(III) hyp ersensitive absorption band and Eu(III) luminescence spectroscopy as well a s FTIR spectra in the investigation of POMs and LnPOM complexes is discusse d. The use of EPR to study magnetic properties and coordination of Gd(III) complexes with POMs, and to probe the local environment of the host metal s ite in terms of symmetry, is presented. (C) 2000 Elsevier Science S.A. All rights reserved.