Substituent effects in cation–π interactions. Recognition of tetramethylammonium chloride by uranyl-salophen receptors

Abstract

The binding affinities of tetramethylammonium chloride to uranyl salophen receptors decorated with X-substituted aromatic pendants (X = OCH₃, CH₃, H, Br, NO₂) point to the importance of resonance effects in cation–π interactions, at variance with the view that field/inductive effects play a dominant role.