Magnetic Sponge with Neutral–Ionic Phase Transitions

Wataru Kosaka, Yusuke Takahashi, Masaki Nishio, Keisuke Narushima, Hiroki Fukunaga, Hitoshi Miyasaka

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


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 (Tc) 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 [Ru2(3,4-Cl2PhCO2)4TCNQ(EtO)2]∙DCE (1-DCE; 3,4-Cl2PhCO2 = 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 (= Tc) 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 Tc 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 Tc for the N–I phase transition via the control of the interstitial guest molecules.

Original languageEnglish
Article number1700526
JournalAdvanced Science
Issue number2
Publication statusPublished - 2018 Feb


  • chain structures
  • donor–acceptor systems
  • host–guest chemistry
  • magnetic properties
  • neutral–ionic phase transitions

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Chemical Engineering(all)
  • Materials Science(all)
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • Engineering(all)
  • Physics and Astronomy(all)


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