A new crown-ether clathrate [15-crown-5][Y(NO3)2(H2O)5][NO3] with switchable dielectric constant behaviour. (20th September 2022)

• Record Type: Journal Article
• Authors: Xiang, Lin; Luo, Wang; Yue, Zhi-Yuan; Huang, Yi-Fang; Wang, Na; Miao, Le-Ping; Ye, Heng-Yun; Shi, Chao
• Is Part Of: New journal of chemistry. Volume 46:Number 38(2022)
• Page Start: 18512
• Page End: 18517
• Publication Date: 2022-09-20
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj03493j
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : A crown-ether clathrate employing a rare-earth ion as the central metal ion was developed, and shown to display switchable dielectric behaviours around a temperature of about 230 K. Abstract : Molecule-based switchable dielectrics with distinct changes of dielectric constant, which enable conversion of electronic properties between different states under external stimuli, are technologically important. The crown-ether clathrate system is a highly promising class of molecule-based switchable dielectrics. Herein, by choosing yttrium nitrate to be assembled with a 15-crown-5 molecule, we synthesized a new crown-ether clathrate, namely [15-crown-5][Y(NO3 )2 (H2 O)5 ][NO3 ] (1 ). One relatively small thermal anomaly peak was observed centered at 230 K ( T tr ) for compound 1 . Single-crystal structures obtained at various temperatures revealed its reversible phase transition to be driven by the synergistic effect of the dynamic changes of the counter [NO3 ] − anions from an ordered to disordered state and the relatively strong thermal vibrations of the 15-crown-5 molecules, along with the rearrangement of [Y(NO3 )2 (H2 O)5 ] + cations in the crystal. Meanwhile, compound 1 also displayed a bistable dielectric response characteristically found in different structural phases. This discovery confirmed the possibility of using compound 1 as a molecule-based dielectric switching material.