Complex formation of alkaline-earth cations with crown ethers and cryptands in methanol solutions
作者:Hans-Jurgen Buschmann
DOI:10.1007/bf00644888
日期:1986.6
The complexation of alkaline-earth cations by different crown ethers, azacrown ethers, and cryptands has been studied in methanol solutions by means of calorimetric and potentiometric titrations. The smallest monocyclic ligands examined form 2∶1 complexes (ratio of ligand to cation) with cations which are too large to fit into the ligand cavity. With the smallest cryptand, only Sr2+ and Ba2+ ions are
已经通过量热和电位滴定在甲醇溶液中研究了不同冠醚、氮冠醚和穴状配体对碱土阳离子的络合。检测到的最小的单环配体与太大而无法放入配体腔的阳离子形成 2:1 的复合物(配体与阳离子的比率)。对于最小的穴状配体,只有 Sr2+ 和 Ba2+ 离子能够形成独特的配合物。在 cryptand (211) 与 Ca2+ 反应的情况下,首次可以单独估计形成排他性和包容性复合物的稳定性常数。与碱金属离子的反应相比,碱土阳离子与穴状配体的反应具有更高的稳定性常数值。这种增加只是由有利的熵贡献引起的。