Two-Component Molecular Materials of 2,5-Diphenyloxazole Exhibiting Tunable Ultraviolet/Blue Polarized Emission, Pump-enhanced Luminescence, and Mechanochromic Response

The development of p -conjugated molecular systems with high-efficiency generation of UV and blue light plays an important role in the fields of light-emitting diodes, fluorescent imaging, and information storage. Herein, supramolecular construction of solid-state UV/blue luminescent materials are assembled using 2,5-diphenyloxazole (DPO) with four typical co-assembled building blocks (1,4-diiodotetrafl uorobenzene, 4-bromotetrafl uorobenzene carboxylic acid, pentafluorophenol, and octafluoronaphthalene). Compared with the pristine DPO sample, the as-prepared two-component molecular materials feature ease of crystallization, high crystallinity, enhanced thermal stability and tunable luminescence properties (such as emissive wavelength, color, fluorescence lifetime, and photoluminescence quantum yield) as well as multicolor polarized emission in the UV/blue region. Moreover, pump-enhanced luminescence and reversible mechanochromic fluorescence (MCF) properties can also be obtained for these molecular solids, which are absent for the pristine DPO sample. Therefore, this work provides a procedure for the facile self-assembly of ordered two-component molecular materials with tunable UV/blue luminescence properties, which have potential application in the areas of light-emitting displays, polarized emission, frequency doubling, and luminescent sensors.