School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Division of Physics & Applied Physics, School of Physical and Mathematics Science, Nanyang Technological University, Singapore 639798, Singapore.
ACS Nano. 2020 Nov 24;14(11):15962-15972. doi: 10.1021/acsnano.0c07416. Epub 2020 Oct 28.
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) and octafluoronaphthalene (OFN, highly soluble, 0.2 × 10 mg mL). 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.
开发基于溶剂化作用失配共晶的有效且绿色的有机功能共晶方法是非常需要和重要的。在此，我们应用了一种绿色两步液辅助研磨共组装（LAGC）方法，从溶剂化作用失配的对苯二炔（TC，难溶，0.2mg/mL）和全氟萘（OFN，高溶，0.2×10mg/mL）中制备全氟萘（TC-OFN）共晶。这种共晶通过常见的溶液处理策略极难制备。更重要的是，这种两步 LAGC 工艺可以使我们能够高效地制备克级 TC-OFN 共晶。所制备的共晶显示了 TC 的固有绿色发射，其光致发光量子产率（13.75%）远高于纯固体 TC 的几乎猝灭发射（0.41%，聚集猝灭（ACQ））。对这些共晶的超快光谱研究证实了 OFN 分子在中断 TC 固体中众所周知的单重态裂变（SF）方面的成功的阻隔功能。此外，这种方法可以使我们很容易地制备荧光 TC-OFN 水基油墨，可用于制备发光画或高发射率的超透明/柔性薄膜。
