Post-application of dry vortex grinding improves the yield of a [2+2] photodimerization: Addressing static disorder in a cocrystal

•[2+2] photodimerization conducted in cocrystal.•Yield improved via mechanochemistry.•Cocrystal exhibits static disorder of a carbon–carbon double bond. A post-application of dry vortex grinding is used to improve a solid-state photodimerization to near quantitative yield that without grinding does not go to completion. Variable temperature X-ray crystal structure data support the vortex grinding to overcome detrimental effects of static disorder that suppresses the yield of the photoreaction in the solid.