Coordination and valence of europium in [Eu(α-2-As2W17O61)2]17- and [Eu(W5O18)2]9-

被引：18

作者：

Antonio, MR

Soderholm, L

Jennings, G

Francesconi, LC

Dankova, M

Bartis, J

机构：

[1] Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA

[2] CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 1998年 / 275卷

基金：

美国国家卫生研究院;

关键词：

europium; L-3; edge; X-ray absorption fine structure; spectroelectrochemistry; valency; polyoxometalate; heteropolyanion;

D O I：

10.1016/S0925-8388(98)00450-2

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Europium L-3 edge X-ray absorption fine structure (XAFS) spectroelectrochemistry was used to determine the valence of europium in [Eu(alpha-2-As2W17O61)(2)](17-) and [Eu(W5O18)(2)](9-). Dilute solutions of these anions in aqueous supporting electrolytes were examined at ambient temperature and at extreme potentials. In situ XANES (X-ray absorption near edge structure) data revealed that Eu is trivalent in both [Eu(alpha-2-As2W17O61)(2)](17-) and [Eu(W5O18)(2)](9-) at rest potential. Furthermore, it was not reduced to Eu2+ by constant-potential bulk electrolysis at significantly reducing potentials under the electrochemical conditions used herein. These results stand in obvious contrast to the redox behavior of [EuP5W30O110](12-), in which Eu3+ is reduced to Eu2+ under similar electrochemical conditions. (C) 1998 Elsevier Science S.A.

引用

页码：827 / 830

页数：4

共 37 条

[1] Implications of the unusual redox behavior exhibited by the heteropolyanion [EuP5W30O110](12-) [J].