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Updated: Jun 28, 2026

Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Observation of ferroelectricity in paramagnetic copper octacyanomolybdate
Kosuke Nakagawa1, Hiroko Tokoro, Shin-Ichi Ohkoshi
1Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Abstract:
We report the observation of ferroelectricity in a copper octacyanomolybdate-based paramagnet, Cu(2)[Mo(CN)(8)].8H(2)O (Cu(II), S = (1)/(2); Mo(IV), S = 0). This compound has a freezing point for the fixation of hydrogen bonding at 150 K. Around this temperature, an enhancement in the ferroelectricity and an increase in the dielectric constant are observed. The ferroelectricity of this system is classified into amorphous ferroelectrics; i.e., the electric poling effect induces an electric polarization. The electric polarization is maintained by the structural local disorder of hydrogen bonding and the three-dimensional CN network. In this ferroelectricity, the crystal structure is a polar group of C(infinityv) after application of an electric field.
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