695-88-5Relevant articles and documents
Directional Intermolecular Interactions for Precise Molecular Design of a High- Tc Multiaxial Molecular Ferroelectric
Yang, Chen-Kai,Chen, Wang-Nan,Ding, Yan-Ting,Wang, Jing,Rao, Yin,Liao, Wei-Qiang,Xie, Yongfa,Zou, Wennan,Xiong, Ren-Gen
, p. 1781 - 1787 (2019/01/26)
Quasi-spherical molecules have recently been developed as promising building blocks for constructing high-performance molecular ferroelectrics. However, although the modification of spherical molecules into quasi-spherical ones can efficiently lower the crystal symmetry, it is still a challenge to precisely arouse a low-symmetric polar crystal structure. Here, by introducing directional hydrogen-bonding interactions in the molecular modification, we successfully reduced the cubic centrosymmetric Pm3m space group of [quinuclidinium]ClO4 at room temperature to the orthorhombic polar Pna21 space group of [3-oxoquinuclidinium]ClO4. Different from the substituent groups of -OH, -CH3, and -CH2, the addition of a -O group with H-acceptor to [quinuclidinium]+ forms directionally N-H?O-C hydrogen-bonded chains, which plays a critical role in the generation of polar structure in [3-oxoquinuclidinium]ClO4. Systematic characterization indicates that [3-oxoquinuclidinium]ClO4 is an excellent molecular ferroelectric with a high Curie temperature of 457 K, a large saturate polarization of 6.7 μC/cm2, and a multiaxial feature of 6 equiv ferroelectric axes. This work demonstrates that the strategy of combining quasi-spherical molecule building blocks with directional intermolecular interactions provides an efficient route to precisely design new eminent molecular ferroelectrics.
