Pyroelectricity in Nonpolar Directions in Crystals: Enantiomeric Disorder and Surface Wetting in Racemic α-Amino-Acids
Pyroelectricity in Nonpolar Directions in Crystals: Enantiomeric Disorder and Surface Wetting in Racemic α-Amino-Acids
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DOI：
10.1021/cg5003644
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发表时间：
2014-08-01
影响因子：
3.8
通讯作者：
Lubomirsky, Igor
中科院分区：
文献类型：
--
作者：
Mishuk, Eran;Weissbuch, Isabelle;Lubomirsky, Igor
沿晶体的非极性方向或从表面显示热电性沿着非极性方向或从表面显示热电性意味着结构无序或极性表面层的存在。极性DL-丙氨酸晶体的非极性{210}面显示出比极性{001}面大得多的热释电效应。类似地，热释电报告从DL-天冬氨酸的中心对称晶体的{110}面。的起源的障碍是由于交换的对映体在特定的手性晶体网站支持的原子-原子势能计算和观察到的非极性晶体的L-丙氨酸故意掺杂相反的对映体的热电效应。这些结果可以解释DL-丙氨酸的针状形态之谜。DL-丝氨酸的{100}面和DL-谷氨酸一水合物晶体的{021}面由于表面润湿而表现出热电性，而源自对映体掺杂的L-丙氨酸晶体的{210}面的热电性可以被解释为同时由于表面润湿和对映体无序而产生。
Display of pyroelectricity along nonpolar directions of crystals or from surfaces implies structural disorder or presence of polar surface layers. Nonpolar {210} faces of polar DL-alanine crystals display far larger pyroelectric effect than that at the polar {001} faces. Similarly, pyroelectricity is reported from {110} faces of centrosymmetric crystals of DL-aspartic acid. The origin of the disorder is due to an interchange of enantiomers at specific chiral crystal sites as supported by atom-atom potential energy computations and by pyroelectric effect observed on the nonpolar crystals of L-alanine intentionally doped with opposite enantiomers. These results should explain the riddle of the needle-like morphology of DL-alanine. The {100} faces of DL-serine and the {021} faces of DL-glutamic acid monohydrate crystals exhibit pyroelectricity due to surface wetting, whereas pyroelectricity originating from the {210} faces of enantiomerically doped L-alanine crystals could be deciphered as arising both from surface wetting and enantiomeric bulk disorder.