EPR spectroscopy of copper and manganese complexes encapsulated in zeolites

被引：47

作者：

Bennur, TH ^{[1
]}

Srinivas, D ^{[1
]}

Ratnasamy, P ^{[1
]}

机构：

[1] Natl Chem Lab, Pune 411008, Maharashtra, India

来源：

MICROPOROUS AND MESOPOROUS MATERIALS | 2001年 / 48卷 / 1-3期

关键词：

zeolite-encapsulated metal complexes; zeozymes; ship-in-a-bottle complexes; EPR spectroscopy; copper complexes; manganese complexes; Schiff base complexes; structure; oxidation catalysts;

D O I：

10.1016/S1387-1811(01)00345-6

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

The structural basis for the enhanced catalytic activities of copper and manganese Schiff base complexes encapsulated in zeolite-Y is investigated by EPR spectroscopy. The study provides an unequivocal evidence for the encapsulation of complexes inside the supercages of zeolite-Y. The EPR spectroscopy distinguishes the encapsulated complexes from the "neat" and surface-adsorbed metal complexes. Neat complexes showed broad EPR spectra corresponding to nearest neighbour spin-spin interactions whereas the zeolite-encapsulated metal complexes showed well resolved metal hyperfine features similar to the spectra in dilute frozen solutions. The spin Hamiltonian parameters reveal a distorted square pyramidal geometry and an increase in the in-plane covalency of metal-ligand bond as a consequence of encapsulation. The observed changes in the molecular electronic structure are correlated to the enhanced catalytic activity of the encapsulated metal complexes. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：111 / 118

页数：8

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