Influence of History of Solution in Crystal Nucleation of Fenoxycarb: Kinetics and Mechanisms
Influence of History of Solution in Crystal Nucleation of Fenoxycarb: Kinetics and Mechanisms
复制标题
溶液历史对苯氧威晶体成核的影响：动力学和机制
DOI：
10.1021/cg4007795
复制
发表时间：
2014
影响因子：
3.8
通讯作者：
Å. Rasmuson
中科院分区：
文献类型：
--
作者：
M. Kuhs;J. Zeglinski;Å. Rasmuson
近1800诱导时间的实验已经进行了苯氧威在异丙醇中的晶体成核的溶液预处理的影响。对于每个预热温度和预热时间，至少进行80次实验以获得统计学有效的结果。感应时间的倒数和预热时间之间的关系可以合理地描述为指数衰减，其时间常数取决于温度，范围高达数天。这种对预热温度的依赖性对应于大于200 kJ/mol的活化能。在足够长的预热时间和高温下，溶液似乎会达到稳定状态，其中“记忆”效应已经消失。密度泛函理论模拟表明，在溶液中的简单二聚体的水平上，晶格中的分子堆积不是化学稳定的构型，而第一溶剂化壳层的模拟揭示了溶质聚集的过程。
Nearly 1800 induction time experiments have been performed on crystal nucleation of fenoxycarb in isopropanol to investigate the influence of solution pretreatment. For each preheating temperature and preheating time, at least 80 experiments were performed to obtain statistically valid results. The relationship between the inverse of the induction time and the preheating time can be reasonably described as an exponential decay having time constants ranging up to days depending on the temperature. This dependence on the preheating temperature corresponds to an activation energy of more than 200 kJ/mol. Given sufficiently long preheating time and high temperature, the solution appears to reach a steady-state where the “memory” effect has disappeared. Density functional theory modeling suggests that the molecular packing in the crystal lattice is not the thermodynamically stable configuration at the level of simple dimers in solution, while modeling of the first solvation shell reveals that solute aggregatio...