Synthesis and Structural Characterization of ... - Jacobs University

Chapter 3
Unpublished Results
However, in 1990, Yamase et al. have reported the first potassium salt of mixedpolyoxotungstate
anion containing lanthanide [Eu 3 (H 2 O) 3 (SbW 9 O 33 )(W 5 O 18 ) 3 ] 16− , in which a
central Eu 3 (H 2 O) 3 core is co-ordinated by one [B-α-SbW 9 O 33 ] 9− unit and three [W 5 O 18 ] 6−
units. 7a
Also, Yamase et al. have reported two structures of lanthanide-containing
tungstoantimonates in 2002, [Ln 2 (H 2 O) 2 (SbW 9 O 33 )(W 5 O 18 ) 2 ] 15− (Ln = Er, Dy, Eu, Sm, Y) and
[Lu 3 (H 2 O) 4 (SbW 9 O 33 ) 2 (W 5 O 18 ) 2 ] 21− . 7b Polyanions [Ln 2 (H 2 O) 2 (SbW 9 O 33 )(W 5 O 18 ) 2 ] 15− consist
of one SbW 9 unit and two [W 5 O 18 ] 6− units. These three units are linked to each other via two
lanthanide ions alternatively. Polyanion [Lu 3 (H 2 O) 4 (SbW 9 O 33 ) 2 (W 5 O 18 ) 2 ] 21− consists of two
[Lu(SbW 9 O 33 )(W 5 O 18 )] 12− groups linked by [Lu(H 2 O) 4 ] 3+ with C 2 configuration. Gouzerh and
coworkers reported the cerium(III) complex with the same lacunary polyoxotungstate [B-α-
SbW 9 O 33 ] 9− , [(SbW 9 O 33 ) 4 {(WO 2 )(H 2 O)} 2 Ce 3 (H 2 O) 8 (Sb 4 O 4 )] 19− which consists of a
tetrahedral assembly of four SbW 9 units connected by two additional six-coordinate tungsten
atoms, three nine-coordinate monocapped square-antiprismatic cerium atoms and a Sb 4 O 4
cluster. 7c Since then, as the best of our knowledge, no lanthanide derivatives of the SbW 9
have been synthesized nor reported so far. Furthermore, there is no lanthanide derivatives of
the Sb 2 W 20 unit have reported previously.
POMs containing lanthanides show interesting properties in areas such as
photoluminescence, catalysis, electrochemistry, and magnetism. 8
Our group has been working in the area of lanthanide-containing polyoxotungstates. 9,10
We have also investigated the interaction of both [As 2 W 19 O 67 (H 2 O)] 14−
As 2 W 19 and
[As 2 W 20 O 68 (H 2 O)] 10− As 2 W 20 (lone-pair containing lacunary precursors) with ytterbium(III)
in aqueous acidic (pH = 2) medium, resulting in both cases in [YbAs 2 W 20 O 68 (H 2 O) 3 ] 7− . 9a
This polyanion consists of two AsW 9 units connected by a triangular [YbW 2 O 2 (H 2 O) 3 ] 11+ unit
which is composed of two 6-coordinated tungsten centers and a 7-coordinated Yb III center, all
carrying one terminal water ligand. 9a
Very recently, our group reported two types of
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