Kosaka Wataru, Takahashi Yusuke, Nishio Masaki, Narushima Keisuke, Fukunaga Hiroki, Miyasaka Hitoshi
Institute for Materials Research Tohoku University 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan.
Department of Chemistry Graduate School of Science Tohoku University 6-3 Aramaki, Aza-Aoba, Aoba-ku Sendai 980-8578 Japan.
Adv Sci (Weinh). 2017 Dec 4;5(2):1700526. doi: 10.1002/advs.201700526. eCollection 2018 Feb.
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 () 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(3,4-ClPhCO)TCNQ(EtO)]∙DCE (; 3,4-ClPhCO = 3,4-dichlorobenzoate; TCNQ(EtO) 2,5-diethoxy-7,7,8,8-tetracyanoquinodimethane; and DCE = 1,2-dichloroethane) that exhibits a one-step N-I transition at 230 K (= ) 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 continuously decreases depending on the content of DCE, which eventually disappears with the complete evacuation of DCE, affording solvent-free compound with the N-state in the entire temperature range (this behavior is reversible). This is an example of tuning the in situ for the N-I phase transition via the control of the interstitial guest molecules.
化合物中性相和离子相之间的电荷不稳定性所引起的相变，即N-I相变，为切换与电子/自旋相关性、偶极子生成以及电荷分布相关的化合物固有属性提供了途径。然而，控制N-I相变的转变温度（）极其困难，目前仅对基于原始材料的化学修饰进行了研究。在此，本文介绍了通过间隙客体分子调节N-I相变的设计概述。本研究报道了一种新型链状配位聚合物[Ru(3,4-ClPhCO)TCNQ(EtO)]∙DCE（；3,4-ClPhCO = 3,4-二氯苯甲酸酯；TCNQ(EtO) = 2,5-二乙氧基-7,7,8,8-四氰基对苯二醌二甲烷；DCE = 1,2-二氯乙烷），该聚合物在230 K（=）时呈现一步N-I转变，其中高温相的N态和低温相的I态分别具有简单顺磁态和亚铁磁相关态。随着DCE含量的增加，持续降低，当DCE完全抽空时最终消失，得到在整个温度范围内均为N态的无溶剂化合物（此行为是可逆的）。这是通过控制间隙客体分子原位调节N-I相变的一个实例。
