几种马来酸氢酯类分光晶体的生长及动力学研究

Growth and Kinetics of Three Esters of Maleate Acid

本文采用溶液降温法生长了马来酸氢十四酯(THM)、马来酸氢十六酯(HHM)和马来酸氢十八酯(OHM)三种同一系列的马来酸氢长碳链酯类分光晶体。主要测定了三种晶体在苯溶剂中的溶解度曲线,随着温度的升高,三种晶体在苯中的溶解度呈增大的趋势,其中在同一温度下THM、HHM和OHM三种晶体溶解度依次减小。动力学研究采用动态循环法测定了晶体的( )和( )晶面的生长速率,结果表明晶体在生长过程中沿(010)方向较难生长,三种晶体随着组成晶体碳链长度的增加,其晶体内部的晶面间距依次增大,而原子进入晶格位置的阻力也相应的增大,生长速率依次减小。晶体结构解析表明三种晶体结构相似属同系列晶体。应用结构规律能很好解释该系列晶体生长习性。

Tetradecyl hydrogen maleate (THM), hexadecyl hydrogen maleate (HHM) and octadecyl hydrogen maleate (OHM)) were successfully grown by the method of slow cooling in solution. The solubility curves in benzene were studied. The results showed that with the increase of the temperature, solubility of the three crystals became larger. At the same temperature, the solubility of THM is the largest, rather than the HHM and OHM. The kinetics experiments had used the method of dynamic loop, measuring the growth rate of ( ) and ( ).The results showed that: the relevant growth rates were decreased and the diffusion resistance of atoms to enter the lattice position became bigger with the increasing of long carbon chains. The link between the difficulty of crystal growth along the (010) direction and the crystal structures was established. The growth rates reduced with the longer carbon chains by the comparative of THM, HHM and OHM. The series of work has instructed the research of X-ray dispersing crystal of maleate acid. These three title esters should be a good candidate for homologous X-ray analyzer crystals.