A Carbazole-1,8-Disulfonamide-Derived Cryptand Receptor for Anion Recognition

A novel cryptand-like anion receptor 1 was synthesized in reasonable yield by a one-step condensation reaction. The UV-vis spectroscopic titrations indicated that cryptand 1 bound AcO- in preference to other monovalent anions (including its competing F- and H2PO4-) in CH3CN, generating a 1:1 binding complex with K-a = 51,000 M-1. Moreover, the crystal structures revealed that the acetate ion was encapsulated inside the cryptand's cavity in a 1:1 manner, through multiple N-HO hydrogen bonds (although having two different crystal forms).

Automated summary

A novel cryptand-like anion receptor 1 was synthesized and shown to preferentially bind AcO-. Crystal structures demonstrated the interaction between the acetate ion and the cryptand through multiple hydrogen bonds.