Heteropolytungstate complexes of the lanthanide elements. Part II. Electronic spectra: a metal–ligand charge-transfer transition of cerium(III)

Abstract

The small nephelauxetic parameters d p for lanthanide heteropolytungstate complexes show that the Ln-0 bond is essentially ionic. The absorption spectra of the EuIIIcomplexes indicate, in each case, site symmetry not higher than tetragonal for the lanthanide; the emission spectra of EUW~,O,~~-and Eu(SiWl,0,s)211-in the solid state agree best with D2d and D4* microsymmetry respectively. The bands causing the brown colours of the CeX1I complexes, whose wavenumbers increase with the CeIV/Cenl redox potential, are assigned to metal-ligand chargetransfer.

Electrochemical Behaviour of First Row Transition Metal Substituted Polyoxotungstates: A Comparative Study in Acetonitrile

“…Therefore, the TBA counter-cations probably induce a larger distortion of the central phosphate groups of the α-B-[PW 9 O 34 ] 10Ϫ subunits. [42,43] Figure 2. IR spectra of (a) K 10 General Electrochemical Behaviour of the Keggin-Type Anions XW 11 M (X ‫؍‬ P, Si) in Acetonitrile Cyclic voltammograms (CV) of the XW 11 M anions in acetonitrile exhibited, in the negative potential region, one to three pairs of cathodic/anodic peaks corresponding to the redox processes of tungsten atoms (Figure 3).…”

Fabrication of lanthanide decatungstate [LnIII/IV(W5O18)2]8−/9− (Ln=CeIV/III, EuIII, and ErIII) thin films using spin-coating from aqueous solutions

“…The crystalline solid of Eu III W 10 film shows bright photoluminescence owing to f-f transitions in Eu 3+ under photoexcitation into O → W LMCT and f-f bands [11][12][13][14][15]. In this work, we recorded emission and excitation spectra of the Eu III W 10 thin film and compared them to those of the crystalline solid.…”

“…In this study, we fabricated thin films of sodium salts of Ln decatungstate Na m [Ln(W 5 O 18 ) 2 ]·nH 2 O (LnW 10 : m = 9 for Ln = Eu III , Ce III , and Er III ; m = 8 for Ln = Ce IV ). Eu III W 10 is known to exhibit strong photoluminescence of Eu 3+ under ultraviolet excitation, and its spectrum is sensitive to a change in the ligand field of Eu 3+ induced by molecular distortion [11][12][13][14][15]. Therefore, Eu III W 10 is a favorable material to be used for evaluating the molecular environment in thin films.…”

Complexation of Heteropoly Anion [MnMo9O32]6− with Lanthanide Ions

“…In this case, the Mo=O term bonds remain equivalent but become elongated only to 1.716 Å, which is less than elongation of analogous bonds in the cis-MoO 2 groups that provide only one O atoms to the coordination surrounding of La. Two O atoms of the cis-MoO 2 group, which simultaneously participate in the complex formation, are also contained in (NH 4 )14 [(MoO 4 )Ce 4 (Mo 7 O 24 ) 4 ] · 38H 2 O [15], (NH 4 ) 28 [Pr 8 Mo 58 O 200 ] · 40H 2 O [32]. The Mo-O int bonds also undergo changes in the course of complex I formation under the influence of the trans-effect of a multiply bonded oxo ligand.…”