Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
Chem Commun (Camb). 2021 May 18;57(40):4950-4953. doi: 10.1039/d1cc01287h.
A series of halogen bonding and chalcogen bonding phenanthroline containing heteroditopic macrocyclic receptors exhibit cooperative recognition of lithium halide (LiX) ion-pairs. Quantitative 1H NMR ion-pair titration experiments in CDCl3 : CD3CN (1 : 1, v/v) reveal a co-bound lithium cation switches on halide anion binding, most notably with the halogen bonding host system. The employment of bis- iodo- and telluromethyl-triazole sigma-hole donor motifs endows contrasting halide anion selectivity and binding affinity, with the halogen bonding ditopic host capable of exclusively binding lithium chloride whereas the chalcogen bonding ditopic receptor displays notable selectivity for lithium iodide over lithium bromide. Preliminary solid-liquid extraction experiments demonstrate the potential of sigma-hole mediated ion-pair recognition as a promising strategy for lithium salt recovery.
一系列含有卤键和硫属键的菲咯啉杂环双位大环受体对卤化锂（LiX）离子对表现出协同识别作用。在 CDCl3：CD3CN（1：1，v/v）中的定量 1H NMR 离子对滴定实验表明，共结合的锂离子可以开启卤化物阴离子的结合，这在卤键主体体系中表现得尤为明显。双碘代和碲代三唑 σ-hole 供体基团的应用赋予了不同的卤化物阴离子选择性和结合亲和力，卤键双位主体能够专一地结合氯化锂，而硫属键双位受体对碘化锂相对于溴化锂表现出显著的选择性。初步的固-液萃取实验表明，σ-hole 介导的离子对识别作为回收锂盐的一种有前途的策略具有潜力。
