Probing and evaluating anion-pi interaction in meso-dinitrophenyl functionalized calix[4pyrrole isomers

Abstract

We investigate anion-pi binding modes in a cis-isomer of 3,5-dinitrophenyl-substituted calix[4]pyrrole with various anions via X-ray crystallographic analyses and compare its binding affinities with those of the corresponding trans-isomer. Sandwich-type anion-pi interactions prove to not only enhancing anion binding abilities but also altering the anion-binding selectivity of the calix[4]pyrrole framework.