Fig. 10
Possible mechanism of photo-triggered phase transition. a Molecular structure of enol, trans-keto, and cis-keto molecules viewed perpendicular and parallel to the salicyl plane obtained by density functional theory calculations. b Overlay of a trans-keto molecule on the (001) face of the enol-(S)-1 crystal in the β-phase. Two independent molecules in the β-phase drawn in yellow and green; the trans-keto molecule is drawn in red. c (001) Plane view of the β-phase before UV irradiation. d Photoisomerization of the crystal in the β-phase. e Photo-triggered phase transition β → γ due to the strain of trans-keto molecules
