Crystal Jumping of Simple Hydrocarbons: Cooling-induced Salient Effect of Bis-, Tri-, and Tetraphenylethene through Anisotropic Lattice Dimension Changes without Thermal Phase Transitions

The thermosalient effect of simple hydrocarbon compounds, including tetraphenylethene, is reported. Single-crystal X-ray diffraction and differential calorimetry analyses of these compounds indicate the absence of thermal phase transitions for their crystal jumps. Thermal expansion coefficient analysis indicates that anisotropic dimension changes of the crystalline lattices are important for this phenomenon.