Exploration of Highly Efficient Blue-Violet Light Conversion Agents for an Agricultural Film Based on Structure Optimization of Triphenylacrylonitrile.

To obtain highly efficient blue-violet light conversion agents used for an agricultural film, six triarylacrylonitrile derivatives and their doping films were prepared. Further, the luminogens have the ability to convert ultraviolet light into blue-violet light and exhibit aggregation-dependent fluorescence emission and high-contrast fluorescence quantum yields from 0.004 to 0.833. On the basis of X-ray single-crystal diffraction analysis and aggregation-induced emission activity tests, the variant fluorescence quantum yields are attributed to intermolecular π-π stacking and phase transition between the crystalline state and amorphous state. In a simulated greenhouse environment, the luminogens exhibit excellent photostability. However, their fluorescence intensity drops to 17-40% of the prime intensity after outdoor radiation for 1 month as a result of the ring-closing oxidation reaction (in the summer). By comprehensively considering the above photophysical properties and mechanical properties of the doping film, 2-([1,1'-biphenyl]-4-yl)-3,3-diphenylacrylonitrile is a potential light conversion agent for an agricultural film in the winter. More importantly, the results indicate that the properties of the light conversion films are expected to be further improved by molecular design, inhibiting the ring-closing oxidation reaction and dispersion of crystalline nanoparticles in the doping film.