Spiro‐Driven Ferroelectric Coordination Polymer Exhibiting Distinct Phase Transitions Under Thermal and Pressure Stimuli

• Published in: Angewandte Chemie International Edition Vol. 64; no. 19; pp. e202500027 - n/a
• Main Authors: Du, Zi‐Yi, Xie, Miao, Qiu, Wenbo, Han, Ding‐Chong, Zhang, Shi‐Yong, Zeng, Ying, Cai, Weizhao, Nakamura, Takayoshi, Huang, Rui‐Kang, He, Chun‐Ting
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.05.2025
• Edition: International ed. in English
• Subjects: Chelation; Controllability; Coordination polymer; Coordination polymers; Electronic equipment; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Ligands; Phase transitions; Polymers; Pressure‐induced phase transition; Thermal‐induced phase transition; Pressure‐induced phase transition; Thermal‐induced phase transition; Ferroelectrics; Coordination polymer
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202500027

Controllable strategies for the design of molecular ferroelectrics have been actively pursued in recent years due to their promising applications in modern electronic devices. In this work, we present a spiro‐driven approach for the design of a new class of molecular ferroelectrics. Using 2‐morpholinoethanol (MEO) as a bidentate chelating ligand and the SCN⁻ anion as a bridging co‐ligand, we obtained a neutral chain‐like ferroelectric coordination polymer, [Cd(MEO)(SCN)₂]. Interestingly, it undergoes both a thermal‐induced phase transition, driven by ring‐conformational flipping of the spiro‐like [Cd(MEO)] fragment, and a pressure‐induced transition, triggered by significant deformation of the spring‐like [Cd(SCN)₂]∞ helical chain. Unlike most previously reported ferroelectric coordination polymers, which often rely on organic cationic guests, this work introduces a new avenue for designing neutral ferroelectric coordination polymers. Overall, the spiro‐driven strategy provides valuable insights and a novel structural motif for the development of advanced molecular ferroelectrics. Here we report the first example of a 1D spiro‐based ferroelectric coordination polymer, which exhibits distinct phase transitions under thermal or pressure stimuli, triggered by the flipping of a spiro ring fragment as well as the deformation of the main chain.