Solvent-induced supramolecular self-assembly in a solid-state A1/A2-difunctionlized pillar[5]arene host

Abstract

An A1/A2 asymmetric-difunctionalized pillar[5]arene bearing n-bormodecyloxy and propargyloxy groups formed four different supramolecular crystal systems depending on the co-crystallization conditions. A cyclic [c2] daisy chain “double-threaded dimer” was obtained when the macrocycle crystallized from a solution containing chloroform and tolualdehyde. Poly[c2] daisy chain, mediated by the solvent molecules, was formed upon crystallization with N,N-dimethylformamide. The supramolecular self-assemblies in the crystal network of the inclusion complex with adiponitrile guest were strongly dependent on the crystallation solvent. The resulting supramolecular assemblies were fully characterized via single-crystal X-ray diffraction analysis. Results of ¹H NMR experiments and isothermal calorimetry titration indicated that their behavior in solution was also solvent-dependent.