Green Grinding-Coassembly Engineering toward Intrinsically Luminescent Tetracene in Cocrystals
Yinjuan Huang, Qiuyu Gong, Jing Ge, Pengpeng Tang, Fei Yu, Lian Xiao, Zongrui Wang, Handong Sun, Jing Yu, Dong‐Sheng Li, Qihua Xiong, Qichun Zhang
Abstract
Developing an effective and green method toward organic functional cocrystals based on the solubility-mismatched coformers is highly desirable and very important. Herein, we applied a green two-step liquid-assisted-grinding coassembly (LAGC) in fabricating tetracene-octafluoronaphthalene (TC-OFN) cocrystals from solubility-mismatched pairs of tetracene (TC, poorly soluble, 0.2 mg mL–1) and octafluoronaphthalene (OFN, highly soluble, 0.2 × 104 mg mL–1). Such cocrystals are extremely difficult to prepare through the common solution-processing strategies. More importantly, this two-step LAGC process could allow us to efficiently prepare TC-OFN cocrystals in gram scale. The as-prepared cocrystals displayed the intrinsic green emission of TC with much higher photoluminescence quantum yield (13.75%) comparing with the pure solid TC with the almost-quenched emission (0.41%, aggregation-caused quenching (ACQ)). The ultrafast spectra study on these cocrystals verifies the successful barrier function of OFN molecules in interrupting the well-known singlet fission (SF) in TC solids. Furthermore, this method can allow us to easily fabricate fluorescent TC-OFN water inks, which can be employed to prepare luminescent paintings or highly emissive ultratransparent/flexible films.