Distinctive Photomechanical Shape Change of p-Phenylenediacrylic Acid Dimethyl Ester Single Crystals Induced by a Spatially Heterogeneous Photoreaction.

Understanding photoreaction dynamics in crystals is important for predicting the dynamic property changes accompanying these photoreactions. In this work, we investigate the photoreaction dynamics of p-phenylenediacrylic acid dimethyl ester (p-PDAMe) in single crystals that show reaction front propagation, in which the photoreaction proceeds heterogeneously from the edge to the center of the crystal. Moreover, we find that p-PDAMe single crystals exhibit a distinctive crystal shape change from a parallelogram to a distorted shape resembling a fluttering flag, then to a rectangle as the photoreaction proceeds.