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

Abstract

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 H 2 PO 4 − ) in CH 3 CN, 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−H•••O hydrogen bonds (although having two different crystal forms). Note pubs.acs.org/joc