Diverse Self-Assembly and Xenon Binding from a Single Mesomeric Macrocycle Component

Abstract

Xenon binding has received considerable interest, but effective hosts remain rare, and the majority of assembly-type hosts are barely explored. Here, we report the synthesis, self-assembly, and xenon inclusion behavior with a homemade mesomeric bisurea–bisthiourea macrocycle. Compared to its racemic counterparts as recently investigated, the single mesomeric macrocycle forms even more comprehensive dimerization assemblies. From the single macrocycle component, up to two pairs of enantiomeric homochiral dimeric assemblies are formed. In the presence of xenon, the assembly diversity was pushed further, and an additional pair of enantiomeric heterochiral assemblies is induced. The diverse assembly comes from the macrocycle component adopting a folded, dissymmetric chiral conformation and undergoing spontaneous symmetry breaking upon cross-buckling together. The formed capsular assemblies possess a sealed, adaptive cavity for accommodating xenon. The cumulative xenon binding constant with the induced heterochiral capsule is about two times higher than the prior one assembled from racemic counterparts. The xenon-induced heterochiral capsule formation with the mesomeric macrocycle again demonstrates that xenon can find its own preferred host from a dynamic self-assembly system and likes to be accommodated by a more spherical van der Waals surrounding.