A hyperspectral camera (HSC) is a camera with great potential to obtain spectral information at each pixel, together with spatial imaging. HSC fluorescence imaging enables the molecular aggregation dynamics of the evaporative crystallization process to be followed in real-time. The key intermediate liquid-like cluster state for the two-step nucleation mechanism is visualized by the fluorescence color changes of mechanochromic luminescent dibenzoylmethanatoboron difluoride derivatives. Three types of emissive species (Crystal, BG-aggregates, and Amorphous) are generated from monomers in solution (low order and density) via liquid-like cluster (high density and low order) during solvent evaporation. These emissive species have partially different aggregated states based on fluorescence decay and fluorescence excitation spectral measurements. In terms of crystallization dynamics, our results indicate that it is important not only to generate supersaturated states but also to maintain the survival time of the liquid-like cluster. Moreover, we demonstrate that HSC fluorescence imaging can be a powerful tool for visualizing heterogeneous molecular aggregation processes.

A phosphonium ylide-based visible light organophotoredox catalyst has been designed and successfully applied to halohydrin synthesis using trichloroacetonitrile and epoxides. An oxidative quenching cycle by the ylide catalyst was established,...

The use of organic nanomaterials in biomedical and optical devices has been widely studied. The key to improving the performance and stability of these devices is to control the fabrication process, which determines the phase stability and photophysical properties. In this study, fluorescence changes were observed during the reprecipitation process of mechanofluorochromic molecules of dibenzoyl(methanato)boron difluoride. The cyan-emission phase (C-phase) was first identified. The time evolution of the resolved fluorescence spectra revealed that the green-emission phase (G-phase) was formed from the amorphous phase with yellow emission via the C-phase, in addition to the direct formation of the G-phase. Combined with the results of the investigation into the thermal properties, the fluorescence changes clearly indicate a two-step nucleation process and Ostwald's rule of stages for polymorph transition, which enables us to not only provide guidance for controlling the fabrication process but also propose the ripening process for organic nanoparticle formation.

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