Under the premise of fixing the ratio of alkali metal ions (sodium, potassium, rubidium, cesium) to ns-CB10 ( n (M + )/ n (ns-CB10) = 2), by changing the acidic environment (hydrochloric acid: 6.0, 9.0 and 12.0 M, sulfuric acid: 6.0, 7.5 and 9.0 M), 14 kinds of complex crystals (I–XIV) with different special structures were successfully prepared. Studies have shown that the crystal morphology difference of ns-CB10-alkali metal ion complex reflects the change of its structural characteristics. The solution environment plays a regulatory role in the interaction between ns-CB10 and alkali metal ions. On the one hand, the size effect of anions in the solvent leads to changes in the structure of the complex. On the other hand, the change of the solution concentration also leads to the difference of crystal configuration. These phenomena reveal the competitive coordination between anions and alkali metal ions in the solvent system.
Lu et al. (2026) studied this question.