Complexes of γ‐Cyclodextrin with Crown Ethers, Cryptands, Coronates, and Cryptates

Cascade complexes are comparable with a set of three interfitting dolls: γ-cyclodextrin (γ-CD)—a ring of eight glucose molecules—accommodates a small crown ether (see model) or cryptand, which in turm can take up a cation. The [12] crown-4-LiSCN complex and the [2.2.1] ⊂ Ca(SCN)2 cryptate from crystalline cascade complexes of stoichiometry 1:1 and 2:1, respectively, with γ-CD from aqueous solution.