meso-Indanyl calix[4]pyrrole receptors

Two new meso-indanyl-substituted calix[4]pyrrole receptors, and , have been synthesized. A range of calix[4]pyrrole host-neutral molecule complexes crystallise from solutions of in a variety of solvents and the structures of four have been elucidated by X-ray crystallography. The F− and Cl− anion affinities of have been measured in acetonitrile, and are significantly different from the corresponding affinities of the prototypical calix[4]pyrrole, the octamethyl-derivative, . ESI-FTICR-MS has been used to determine the relative F− and Cl− anion affinities of receptors and in methanol–acetonitrile solution. Deprotonation of and by fluoride is observed (under the conditions of the MS experiment).