双冠醚配位作用的热力学性质 Ⅲ.醚型和酯型双冠醚与金属阳离子配位作用的量热滴定

Complexation Thermodynamics of Bis (crown ether) s Ⅲ. Calorimetric Titration of Complexation of the Etheric and Esteric Types of Bis (crown ether)s with Metal Cations

本文用量热滴定法测定了醚型、酯型双(12-冠-4)与钠离子,醚型双(15-冠-5)与钾、铊离子在8∶2甲醇-水溶液中,25℃时配位作用的热力学性质.实验结果表明,所有的双冠醚均与阳离子形成了夹心型配位化合物,并与带臂冠醚和母体冠醚的实验结果作了比较.从热力学的观点,讨论了双冠醚的桥联结构对稳定性的影响.

Calorimetric titration in 8:2 methanol-water at 25℃ were performed to give the complex stability constants and thermodynamic properties for the complexation of the etheric, esteric types bis (12-crown-4)s with sodium ion and estric types bis (15-crown-5)s with potassium and thallium ions. All bis (crown ether)s were shown to form intramolecular '2: l' sandwich-type complexes, and compared with the results of side arm and maternal crown ether. The effects of the bridging chain constitution between the two crown ether units upon complex stability are discussed from a viewpoint of thermodynamics.