Synthesis and Spectroscopic Study of Europium(III) in Heteropolyanion [EuP₅W₃₀O₁₁₀]^12-

Abstract

The heteropolyanions of Preyssler anion [NaP5 W30 O110]14-and its europium-encrypted derivative [EuP5 W30 O110]12 were prepared and spectroscopically characterized. The compositions of these heteropolyanions were verifred based oji tle results from elemental and thermogravimetric analysis and the data of spectrophotometric determination of tungsten contents. Absorption in the UV-vis and IR region and luminescence spectra, as well as results of the laser-induced europium ion luminescence spectroscopy, obtained for solid complexes and their solutions, were analysed. Both in solid and solution the europium-encrypted derivative las three water molecules of hydration.

EPR Study of Gadolinium(III) Complexes with Heteropolyanions: [Gd(SiW11O39)2]13-and [GdP5W30O110]12-

“…[5,16], and 3 inner sphere H2O's in the case of europium-encrypted Preyssler anion, both in aqueous solution and the solid [4,5]. In the case of the gadolinium-encrypted complex the Gd3+ ion is unsymmetrically encapsulated with two bounded (probably linearly) water molecules and most likely the third water molecule is not directly encrypted [4,5].…”

“…The gadolinium-encrypted heteropolyanion [G dΡ5W30O110]12-was prepared from the parent Preyssler anion according to the previously described method [1,4,5]. Substitution of Na+ by Gd3+ was made according to the reaction The gadοliniumsandwiched complex [Gd(SiW11 O39)2H3-was obtained from the ligand K8[SiW11O39] .…”

Spectroscopic Studies of Polyoxometalates and their Complexes with Lanthanide(III) Ions in Solution

“…In our study the Preyssler heteropolyanion [ΝaP 5W30 Ο 110] 14-and its europium-encrypted heteropolyanion [EuP 5 W30 O 110] 122-were spectroscopically characterized using absorption and luminescence spectra as well as results of the laser-induced europium ion luminescence spectroscopy recorded for solid complexes and their solutions [38]. It was found three water molecules in the inner sphere of Eu(III) in the europium-encapsulated complex in aqueous solution and in the solid state.…”

Polyoxo Anions: Synthesis and Structure

“…[147][148][149][150][151][152] Spectroscopic, luminescence, and ESR studies have been reported for some of the lanthanide-encrypted anions. [153][154][155][156][157][158] All the anions show reversible tungsten-reduction processes, and there is some evidence to suggest that divalent europium is generated in partially reduced [Eu(H 2 O)P 5 W 30 O 110 ] nÀ . 159 Proton exchange on the internal water molecule has been traced by NMR measurements.…”