695-88-5Relevant academic research and scientific papers
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.
Process for the preparation of derivatives of quinuclidine substituted in the 3 position
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, (2008/06/13)
Process for the preparation of compounds of the formula: STR1 in which X is H, Cl, Br, I or OH, in which 3-methylene quinuclidine is reacted with an aluminum hydride, in an appropriate solvent and in the presence of a catalytic quantity of a halide of a transition metal, the molar ratio EQU1 being at least equal to 0.6, the product formed is reacted in situ with an ester, and then the product thus formed is reacted in situ with an electrophilic reactant which is capable of yielding an atom or group X as defined with reference to formula (I). The compounds of formula (I) can be used for the preparation of medicaments.
