Crystal Structures of Resorcin[4]arene and Tetramethylated Resorcin[4]arene Complexes Incorporating L-Carnitine through Cation–π Interaction

Resorcin[4]arene and tetramethylated resorcin[4]arene form complexes with L-carnitine, whose crystal structures were determined. Each complex contains two carnitine ligands in the asymmetric unit, each of which is incorporated into the cavity of the macrocyclic receptor through cation–π interactions between the trimethylammonium moiety of the ligand and π–rings of the receptor.