Role of latent heat in chiral symmetry breaking transition in the crystallization of 1,1′-binaphthyl
Role of latent heat in chiral symmetry breaking transition in the crystallization of 1,1′-binaphthyl
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DOI：
10.1002/chir.10187
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发表时间：
2003-03-01
期刊：
影响因子：
2
通讯作者：
Osanai, S
中科院分区：
文献类型：
--
作者：
Asakura, K;Hayashi, M;Osanai, S
本文研究了1，1 '-联萘在过冷熔融态结晶过程中的潜热对手性对称性破缺跃迁的影响。用红外热像仪监测结晶系统的温度变化。在无搅拌的结晶系统中，由于多晶聚集体生长前沿的潜热耗散而引起的温升约为20 ℃。1，1 ′-联萘的外消旋混合物和外消旋化合物的熔点分别为145 ℃和158 ℃。因此，当熔体初始温度略低于145 ℃时，结晶过程中产生的潜热可以改变熔体的结晶行为。监测未搅拌和搅拌结晶系统中的温度变化。在搅拌结晶系统中，即使在熔体的初始温度比145 ℃低约2 ℃的情况下，温度在结晶开始后立即上升约4 ℃。这表明搅拌作为手性对称性破缺转变的临界参数的作用不仅是克隆手性晶体，而且还增强了由于二次成核引起的潜热耗散。(C)2003 Wiley-Liss，Inc.
The influence of latent heat dissipated by the crystallization of 1,1'-binaphthyl in its supercooled molten state on the chiral symmetry breaking transition was investigated. Temperature change in the crystallization system was monitored by infrared thermocamera. Temperature rise due to the dissipation of latent heat in the growing front of polycrystalline aggregate was about 2degreesC in an unstirred crystallization system. The melting point of racemic mixture and racemic compound of 1,1'-binaphthyl is 145degreesC and 158degreesC, respectively. The latent heat generated by the crystallization could thus change the crystallization behavior when the initial temperature of the melt was slightly lower than 145degreesC. The temperature change in both unstirred and stirred crystallization systems was monitored. In the stirred crystallization system, even in the case when the initial temperature of the melt was about 2degreesC lower than 145degreesC, the temperature rose by about 4degreesC immediately after the onset of crystallization. This indicates that the role of stirring as the critical parameter for the chiral symmetry breaking transition is not only to clone the chiral crystals but also to enhance the dissipation of latent heat due to secondary nucleation. (C) 2003 Wiley-Liss, Inc.