Fuel-Driven Transient Crystallization of a Cucurbit[8]uril-Based Host-Guest Complex

Angew Chem Int Ed Engl. 2019 Nov 18;58(47):16850-16853. doi: 10.1002/anie.201910161. Epub 2019 Oct 25.

Abstract

Transient self-assembling systems often suffer from accumulation of chemical wastes that interfere with the formation of pristine self-assembled products in subsequent cycles. Herein, we report the transient crystallization of a cucurbit[8]uril-based host-guest complex, preventing the accumulation of chemical wastes. Base-catalyzed thermal decarboxylation of trichloroacetic acid that chemically fuels the crystallization process dissolves the crystals, and produces volatile chemical wastes that are spontaneously removed from the solution. With such self-clearance process, no significant damping in the formation of the crystals was observed. The morphology and structural integrity of the crystals was also maintained in subsequent cycles. The concept may be further extended to obtain other temporally functional materials, quasicrystals, etc., based on stimuli-responsive guest molecules.

Keywords: dissipative self-assembly; host-guest systems; non-equilibrium processes; supramolecular chemistry; transient crystallization.