Spectroscopic properties of neodymium(III)-containing polyoxometalates in aqueous solution

The spectroscopic properties of the neodymium(III)-containing polyoxometalates (POMs) [Nd(PW11O39)(2)](11-) , [Nd(PMO2W9O39)(2)](11-) [Nd(PMo4W7O39)(2)(11-) , [Nd(PMO6W5O39)(2)](11-) , [Nd(SiMo2W9O39)(2)](13-) , [Nd(P2W17O61)(2)](17-) , [NdW10O36](9-) , [NdP5W30O110](12-) and [NdAS(4)W(40)O(140)](25-) are described. Absorption spectra of aqueous solutions of the complexes have been recorded and the transition intensities are parameterised in terms of the Judd-Ofelt intensity parameters Omega(lambda) (lambda = 2, 4, 6). Marked differences were found between the luminescence lifetimes of the complexes of the type Nd(POM) and those of the type Nd(POM)2, due to a better shielding of the neodymium(III) ions from the bulk water molecules in the latter type of complexes. (c) 2005 Elsevier B.V. All rights reserved.