三水合高氯酸镨与18-冠-6配合的研究

采用半微量相平衡方法研究了三元体系Pr(ClO4)3.3H2O-18C6-C2H5OH在298.15K的溶解度, 测定了饱和溶液的折光率。该体系在298.15K时生成两种化学计量的配合物: Pr(ClO4)3.18C6.3H2O(1)和Pr(ClO4)3.2(18C6).3H2O(2)。制备了两种固态配合物, 用化学分析, IR, DTG和TG研究了配合物的组成和性质, 采用量热法, 测定了298.15K时18C6, 配合物1和2在乙醇中的积分溶解热, 以及Pr(ClO4)3.3H2O在18C6-C2H5OH溶液中的积分溶解热。利用本文设计的热化学循环, 求得了两种配合物的标准生成焓。

Study on complexes of trihydrated praseodymium perchlorate with 18 -crown-6

The solubilities of the ternary system, Pr(ClO4)3.3H2O-18C6- C2H5OH, have been investigated by a semimicro method at 298.15K for study of phase equilibrium and the refractive indexes of saturated solutions have been determined. The results indicate that there are two kinds of coordination compounds formed in the system, their chemical compositions are: Pr(ClO4)3.18C6.3H2O(1) and Pr(ClO4)3.2(18C6).3H2O(2). The two solid coordination compounds have been prepared. The composition and properties of the complexes have been investigated by chemical analysis, IR, TG and DTG. The integral heats of solution of Pr(ClO4)3.3H2O in 18C-C2H5OH solution, the complexes (1) and (2) in C2H5OH, and 18C6 in C2H5OH have been measured calorimetrically at 298.15K. By means of a thermochemical cycle suggested in this paper, the standard molar enthalpies of formation for two complexes were obtained.