Structural mapping of mechanically flexible photoluminescent and photodynamic molecular crystals

Mechanically flexible luminescent organic crystals have become an essential part of modern technologies like optoelectronics, while photoluminescent crystals, able to transform light energy into mechanical motions, are a promising choice for actuating and photonic devices. Here, we present our findings on how quantitative structural mapping can rationalize the change in phosphorescence emission, as a function of the flexibility of elastic single crystals of dibenzothiophene and its brominated derivate. The dibenzothiophene crystals show dual fluorescence (FL) and room temperature phosphorescence (RTP), while the bromo derivative only shows RTP. We further present how the photosalient behavior of room temperature phosphorescent molecular crystals, based on organoboron containing Lewis acid-base adducts, can be explained by crystal-to- crystal [2+2] cycloaddition reactions as the driving force. The latter crystals display short-lived room temperature phosphorescence, while the photodynamic events are accompanied by enhancement of their phosphorescence intensity.Mechanically flexible luminescent organic crystals have become an essential part of modern technologies like optoelectronics, while photoluminescent crystals, able to transform light energy into mechanical motions, are a promising choice for actuating and photonic devices. Here, we present our findings on how quantitative structural mapping can rationalize the change in phosphorescence emission, as a function of the flexibility of elastic single crystals of dibenzothiophene and its brominated derivate. The dibenzothiophene crystals show dual fluorescence (FL) and room temperature phosphorescence (RTP), while the bromo derivative only shows RTP. We further present how the photosalient behavior of room temperature phosphorescent molecular crystals, based on organoboron containing Lewis acid-base adducts, can be explained by crystal-to- crystal [2+2] cycloaddition reactions as the driving force. The latter crystals display short-lived room temperature phosphorescence, while the photodynamic events are accompanied by enhancement of their phosphorescence intensity.C