Abstract
Hollow organic molecular cocrystals comprised of 9‐methylanthracene‐1,2,4,5‐tetracyanobenzene (9MA‐TCNB) and naphthalene‐1,2,4,5‐tetracyanobenzene (NAPH‐TCNB) were fabricated using a surfactant‐mediated co‐reprecipitation method. The crystals exhibit a narrow size distribution that can be easily tuned by varying the concentration of surfactant and incubation temperature. The rectangular crystals possess symmetrical twinned cavities with an estimated storage volume on the order of 10−10 L. An aqueous dye solution can be incorporated into the cavities during crystal growth and stored inside for up to several hours, confirming the sealed nature of the hollow chambers. Our results demonstrate that it is possible to harness non‐classical crystal growth to fabricate organic molecular crystals with novel topologies.
A naphthalene‐1,2,4,5‐tetracyanobenzene cocrystal with two symmetrical closed cavities can be grown using surfactant‐mediated coprecipitation combined with gentle agitation. During growth, the molecular crystal microcapsule can be filled with a fluorescent dye that remains contained for hours. The images show a single dye‐filled organic cocrystal viewed using transmission, polarized, and fluorescence microscopy.