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Updated: May 21, 2026

Synthesis and Characterization of Functionalized Metal-organic Frameworks
Published on: September 5, 2014
K4Fe4P5O20: a new mixed valence microporous compound with elliptical eight-ring channels
Zhangzhen He1, Weilong Zhang, Wendan Cheng
1State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Mater, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China. hezz@fjirsm.ac.cn
Abstract:
A new small-pore compound K(4)Fe(4)P(5)O(20) was obtained by conventional solid-state reaction in a closed crucible. The crystal structure is constructed by Fe(4)P(5)O(20) units forming chains along the c axis and elliptical eight-ring channels on the a-b plane in which K cations locate inside. Such structural characteristics seem to be quite similar to those seen in the natrolite family. However, Fe ions in K(4)Fe(4)P(5)O(20) have trigonal-bipyramidal instead of common tetrahedral coordination. Furthermore, our experimental results combined from magnetic susceptibility and (57)Fe Mössbauer spectrum measurements show mixed valence Fe(3+)/Fe(2+) in the titled material. To the best of our knowledge, this is the first example that contains mixed valence iron ions in a so-called natrolite framework.
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