冠醚配合物的热力学性质的研究(Ⅰ)——若干金属离子与18-冠-6及其甲基衍生物的配位反应的量热滴定研究

A STUDY ON COORDINATION REACTIONS OF METHYL DERIVATIVES OF 18-CROWN-6 WITH SOME METAL IONS BY THERMOMETRIC TITRATION

量热滴定法是研究冠醚的溶液配位化学的重要方法,一次滴定可同时求出稳定常数K和反应焓△H,而且是测定后者唯一直接而准确的方法,Izatt等作了大量的研究。但因量热滴定需要精细的操作,且计算复杂,故应用此法的实验室不多。在我国,用量热滴定法于溶液配位化学的研究似未见报道。

Thermodynamic functions of the coordination reactions of newly synthesized 2,3-benzo-8,15-dimethyl-18-crown-6 with several alkali and alkaline earth chlorides in aqueous solution were studied by calorimetric titration. The results show that only barium-ion coordinated with the crown, while the other alkaline earth and alkali metal ions did not coordinate to any detectable degree because they do not have enough activity toward the crown due to its limited solubility in solution (0.005M) and very small enthalpy of reaction.