Elastic and Bendable Caffeine Cocrystals: Implications for the Design of Flexible Organic Materials

Crystalline spring: Single crystals formed from caffeine, 4-chloro-3-nitrobenzoic acid, and methanol (1:1:<1) have an interlocked structure with weak interactions in the three perpendicular directions, as well as solvent channels, and display reversible elastic bending. Excellent conservation of long-range order even after many bending cycles is observed, thus demonstrating the opportunities for flexible organic materials.