Unprecedented {Fe14 }/{Fe10 } Polyoxotungstate-Based Nanoclusters with Efficient Photocatalytic H2 Evolution Activity: Synthesis, Structure, Magnetism, and Electrochemistry.
Chemistry
; 22(31): 10983-9, 2016 Jul 25.
Article
em En
| MEDLINE
| ID: mdl-27345965
ABSTRACT
Novel Fe10 and Fe14 clusters [Rb9 Cs4 H37 Fe10 O34 (A-α-PW9 O31 )3 (OH)3 ]â
36 H2 O (1) and [H3 Rb3 Fe14 (OH)12 (PO4 )6 (B-α-PW9 O34 )2 ]â
21 H2 O (2) were synthesized and characterized in the solid state by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), and magnetic studies, and in solution by electrochemistry. Cluster 1 is a decameric Fe(III) polyanionic cluster encapsulating a cesium atom in the center. Cluster 2 is a unique tetradecanuclear Fe(III) sandwich structure with phosphate-linked units featuring two quasicubic Fe4 O4 moieties. Apparently, 2 has the highest nuclearity of all known Fe(III) sandwich-type polyoxometalate clusters. Clusters 1 and 2 also act as photocatalysts with platinum as cocatalyst for H2 evolution from light-driven water splitting. Changes in the cyclovoltammetric patterns with variations in pH were observed for 1 and 2, most likely due to intermolecular interactions among the high-nuclearity Fe(III) cluster cores and subsequent changes in the acid-base properties of the two reduced POMs. Magnetic studies provide evidence of antiferromagnetic interactions in 1 and 2. TGA showed that complexes 1 and 2 decompose between 580 and 590 °C.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article