Open AccessMagnetic Sponge with Neutral–Ionic Phase Transitions
Author(s) -
Kosaka Wataru,
Takahashi Yusuke,
Nishio Masaki,
Narushima Keisuke,
Fukunaga Hiroki,
Miyasaka Hitoshi
Publication year - 2018
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201700526
Subject(s) - phase transition , ionic bonding , phase (matter) , molecule , materials science , tetracyanoquinodimethane , chemical physics , paramagnetism , transition temperature , chemistry , crystallography , ion , thermodynamics , organic chemistry , condensed matter physics , physics , superconductivity
Phase transitions caused by the charge instability between the neutral and ionic phases of compounds, i.e., N–I phase transitions, provide avenues for switching the intrinsic properties of compounds related to electron/spin correlation and dipole generation as well as charge distribution. However, it is extremely difficult to control the transition temperature ( T c ) for the N–I phase transition, and only chemical modification based on the original material have been investigated. Here, a design overview of the tuning of N–I phase transition by interstitial guest molecules is presented. This study reports a new chain coordination‐polymer [Ru 2 (3,4‐Cl 2 PhCO 2 ) 4 TCNQ(EtO) 2 ]∙DCE ( 1‐DCE ; 3,4‐Cl 2 PhCO 2 − = 3,4‐dichlorobenzoate; TCNQ(EtO) 2 2,5‐diethoxy‐7,7,8,8‐tetracyanoquinodimethane; and DCE = 1,2‐dichloroethane) that exhibits a one‐step N–I transition at 230 K (= T c ) with the N‐ and I‐states possessing a simple paramagnetic state and a ferrimagnetically correlated state for the high‐ and low‐temperature phases, respectively. The T c continuously decreases depending on the content of DCE, which eventually disappears with the complete evacuation of DCE, affording solvent‐free compound 1 with the N‐state in the entire temperature range (this behavior is reversible). This is an example of tuning the in situ T c for the N–I phase transition via the control of the interstitial guest molecules.