Hyun Oh Ju, Joong Kim Min, Choi Jaewon, Chan Jeong Hae, Kuk Kim Sung
Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju, 52828, Korea.
Nonsan Carbon Neutrality Support Center, Konyang University, Nonsansi, 32992, Korea.
Chemistry. 2025 Feb 3;31(7):e202403868. doi: 10.1002/chem.202403868. Epub 2024 Dec 13.
We have synthesized a new ion pair receptor (2) consisting of a cone-calix[4]arene bearing a combination of ethyl esters and ethers as a cation binding site and a calix[4]pyrrole subunit acting as an anion binding site. Ion pair receptor 2 complexes LiCl, NaCl, and CsCl among alkali metal chloride salts with distinct complexation modes and affinities in 10 % methanol-d in chloroform-d. For instance, relatively small Li and Na cations are bound to the oxygen atoms of the functionalized calix[4]arene lower rim with Cl being hydrogen bonded to the calix[4]pyrrole NHs while the larger Cs cation is bound to the cone-shaped calix[4]pyrrole cavity via a π-cation interaction. By contrast, in the co-presence of all MCl salts (M=Li, Na, K, Rb, and Cs), receptor 2 binds LiCl with complete selectivity. Besides, receptor 2 is capable of extracting LiCl selectively into a chloroform or a dichloromethane organic phase from its solid source containing all other MCl salts.
我们合成了一种新的离子对受体（2），它由一个带有乙酯和醚组合作为阳离子结合位点的锥形杯[4]芳烃以及一个作为阴离子结合位点的杯[4]吡咯亚基组成。在10%的氘代甲醇 - 氘代氯仿中，离子对受体2能与碱金属氯化物盐中的氯化锂、氯化钠和氯化铯形成配合物，且具有不同的络合模式和亲和力。例如，相对较小的锂和钠阳离子与功能化杯[4]芳烃下缘的氧原子结合，而氯则通过氢键与杯[4]吡咯的氨基氢相连，而较大的铯阳离子则通过π - 阳离子相互作用与锥形杯[4]吡咯腔结合。相比之下，在所有MCl盐（M = 锂、钠、钾、铷和铯）共存的情况下，受体2能完全选择性地结合氯化锂。此外，受体2能够从含有所有其他MCl盐的固体源中选择性地将氯化锂萃取到氯仿或二氯甲烷有机相中。
