Issue 10, 2016

The cation-dependent structural phase transition and dielectric response in a family of cyano-bridged perovskite-like coordination polymers

Abstract

A family of cyano-bridged perovskite-like coordination polymers (CPs), [(CH3)nNH4−n]2[KFe(CN)6] (n = 1 (1), 2 (2), 3 (3), and 4 (4)), were synthesized and characterized. The differential scanning calorimetry measurements and variable-temperature single-crystal X-ray structural analyses revealed that, owing to the deformation of the host framework as well as the dynamic transition of the guest cation between the static/ordered and dynamic/disordered states, the four CPs undergo structural phase transitions (at 429, 226, 316, and 350 K, respectively) with the symmetry breakings dependent on the symmetries of the encapsulated guest cations. The modulated differential scanning calorimetry measurement suggested that the phase transitions of 1 and 3 have more striking kinetic processes related to their drastic deformation of the host framework as well as a very significant alteration of the host–guest interaction during the phase transition. Moreover, accompanying the transitions between low- and high-temperature phases, the step-like transitions between low and high dielectric states were observed in 1–3, and the corresponding change in amplitude of the dielectric constant is dependent on the total dipole moment of each cage in the high-temperature phase. The investigation on these host–guest CPs deepens the understanding of the relationship between the dipole moment of guest cations and the dielectric behaviour of materials, shedding light on the search for new switchable molecular dielectrics.

Graphical abstract: The cation-dependent structural phase transition and dielectric response in a family of cyano-bridged perovskite-like coordination polymers

Supplementary files

Article information

Article type
Paper
Submitted
07 sep 2015
Accepted
20 okt 2015
First published
20 okt 2015

Dalton Trans., 2016,45, 4224-4229

The cation-dependent structural phase transition and dielectric response in a family of cyano-bridged perovskite-like coordination polymers

W. Xu, S. Chen, Z. Hu, R. Lin, Y. Su, W. Zhang and X. Chen, Dalton Trans., 2016, 45, 4224 DOI: 10.1039/C5DT03481G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements