We report the synthesis of a new synthetic cavitand receptor with an embedded thiourea moiety directed at effective molecular recognition of ion pairs. Initial prospects towards the use of cavitands in biomimetic carbocationic cyclizations have been carried out, employing ionic guests as stable surrogates for putative substrates and intermediates. The cavitand displays tight binding with tetramethylammonium salts, with unforeseen slow exchange kinetics of both cation and anion components.