Jumping Crystals of Pyrene Tweezers: Crystal-to-Crystal Transition Involving π/π-to-CH/π Assembly Mode Switching

Crystals of pyrene tweezers 1 with interdigitating pyrenyl blades jump vigorously at around 160 degrees C. Singlecrystal X-ray diffraction analysis before jumping revealed the presence of a pyrene tetrad in the crystal lattice, where four pyrenyl blades are pi-stacked on top of each other. Upon heating the crystal to induce the jumping event, inner two pyrenyl blades in the pyrene tetrad probably rotate to switch off their pi-stacking interaction with the neighboring outer pyrenyl blades and form new CH-pi bonds. Different from reported salient crystals, our crystal jumps with the release of CHCl3 as inclusion solvent.