摘要
用量热滴定法于298.15K测定了除钪、钷以外的全部十五种稀土(Ⅲ)高氯酸盐与苯并-15-冠-5在乙腈溶液中的配位作用.借助计算机算出了配合物的稳定常数和配位焓,进而算出了配位自由能和配位熵.结果表明:十五种稀土(Ⅲ)离子与苯并-15-冠-5都可以配位,配位焓为正值;La^(3+)配合物最稳定,Ce^(3+)次之,其余稀土(Ⅲ)离子配合物的稳定性变小,但彼此差别不大,在Tb处有突变;熵在配合物形成时起稳定化作用.
The coordination reaction of benzo-15-crown-5 with fifteen rare earth (La, Ce Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y) perchlorates in acetonitrile was determined at 298. 15K by calorimetric titration. The stability constants of coordination compounds and enthalpies of coordination reaction were calculated by Using computer. Furthermore, the values of free energy and entropy of coordination reaotion were obtained. The results show that these rare earth ions (ⅠⅡ) can coordinate with benzo-15-crown-5 and all enthalpy changes are endothermic. The coordination compound of La^3+ is the most stable one, followed by Ce^3+ compound, among the rest compounds there is no distinot difference in stability, and a sudden change was ohserved at Tb. The coordination compounds are stabilized by entropic effects.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1990年第5期452-458,共7页
Acta Chimica Sinica
