Unusual Sequential Reversible Phase Transitions Containing Switchable Dielectric Behaviors in Cyclopentyl Ammonium 18-Crown-6 Perchlorate

详细信息    查看全文

• 作者：Yun-Zhi Tang ; Zhi-Feng Gu ; Jian-Bo Xiong ; Ji-Xing Gao ; Yi Liu ; Bin Wang ; Yu-Hui Tan ; Qing Xu
• 刊名：Chemistry of Materials
• 出版年：2016
• 出版时间：June 28, 2016
• 年：2016
• 卷：28
• 期：12
• 页码：4476-4482
• 全文大小：541K
• 年卷期：0
• ISSN：1520-5002

文摘

Multisequential reversible phase transitions based on molecular materials have important applications in ferroelastic materials, ferroeletric materials, switchable dielectric materials, and temperature-controlling materials. Here, we report that a new compound, [Hcpa-(18-crown-6)]⁺[ClO₄]⁻ (1) (where Hcpa represents protonated cyclopentylamine cations) displays unusual multisequential reversible phase transitions accompanied by switchable dielectric behaviors. The stepwise synergistic disordering of Hcpa cations and ClO₄^– anions leads to the sequential reversible phase transitions and symmetry breaking. These unusual reversible phase transitions were further confirmed by the variable-temperature powder X-ray diffractometry (PXRD), thermal anomalies of differential scanning calorimetry (DSC) measurements, and abrupt dielectric anomalies in the heating and cooling processes.