10.1021/jacs.8b13223.s004
Chen-Kai Yang
Chen-Kai
Yang
Wang-Nan Chen
Wang-Nan
Chen
Yan-Ting Ding
Yan-Ting
Ding
Jing Wang
Jing
Wang
Yin Rao
Yin
Rao
Wei-Qiang Liao
Wei-Qiang
Liao
Yongfa Xie
Yongfa
Xie
Wennan Zou
Wennan
Zou
Ren-Gen Xiong
Ren-Gen
Xiong
Directional
Intermolecular Interactions for Precise
Molecular Design of a High‑<i>T</i><sub>c</sub> Multiaxial
Molecular Ferroelectric
American Chemical Society
2019
OH
ferroelectric
substituent groups
Curie temperature
6 equiv
building blocks
quinuclidinium
quasi-spherical ones
crystal symmetry
457 K
CH
quasi-spherical molecule building blocks
Directional Intermolecular Interactions
crystal structure
Precise Molecular Design
Systematic characterization
hydrogen-bonding interactions
modification
oxoquinuclidinium
Pna 2 1 space group
room temperature
multiaxial feature
2019-01-07 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Directional_Intermolecular_Interactions_for_Precise_Molecular_Design_of_a_High_i_T_i_sub_c_sub_Multiaxial_Molecular_Ferroelectric/7597553
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 <i>Pm</i>3̅<i>m</i> space group of [quinuclidinium]ClO<sub>4</sub> at room temperature to the orthorhombic polar <i>Pna</i>2<sub>1</sub> space group of [3-oxoquinuclidinium]ClO<sub>4</sub>. Different from the substituent groups of −OH, −CH<sub>3</sub>, and CH<sub>2</sub>, the addition of a O
group with H-acceptor to [quinuclidinium]<sup>+</sup> forms directionally
N–H···OC hydrogen-bonded chains, which
plays a critical role in the generation of polar structure in [3-oxoquinuclidinium]ClO<sub>4</sub>. Systematic characterization indicates that [3-oxoquinuclidinium]ClO<sub>4</sub> is an excellent molecular ferroelectric with a high Curie
temperature of 457 K, a large saturate polarization of 6.7 μC/cm<sup>2</sup>, 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.