Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan).
JST-PRESTO, Honcho 4-1-8, Kawaguchi, Saitama 332-0012 (Japan).
Angew Chem Int Ed Engl. 2015 Sep 21;54(39):11550-4. doi: 10.1002/anie.201505168. Epub 2015 Aug 19.
Inspired by the bicontinuous ionic-network structure of ionic liquids (ILs), we developed a new family of photofunctional ILs which show efficient triplet energy migration among contiguously arrayed ionic chromophores. A novel fluorescent IL, comprising an aromatic 9,10-diphenylanthracene 2-sulfonate anion and an alkylated phosphonium cation, showed pronounced interactions between chromophores, as revealed by its spectral properties. Upon dissolving a triplet sensitizer, the IL demonstrated photon upconversion based on triplet-triplet annihilation (TTA-UC). Interestingly, the TTA-UC process in the chromophoric IL was optimized at a much lower excitation intensity compared to the previous nonionic liquid TTA-UC system. The superior TTA-UC in this IL system is characterized by a relatively high triplet diffusion constant (1.63×10(-6) cm(2) s(-1)) which is ascribed to the presence of ionic chromophore networks in the IL.
受离子液体（ILs）双连续离子网络结构的启发，我们开发了一类新型光功能化 ILs，其具有连续排列的离子发色团之间的高效三重态能量迁移。一种新型荧光 IL，包含芳基 9,10-二苯基蒽 2-磺酸盐阴离子和烷基化的鏻阳离子，显示出发色团之间的显著相互作用，这从其光谱性质中可以看出。当溶解三重态敏化剂时，该 IL 表现出基于三重态-三重态湮灭（TTA-UC）的光上转换。有趣的是，与先前的非离子液体 TTA-UC 体系相比，在该发色团 IL 中，TTA-UC 过程可以在低得多的激发强度下进行优化。该 IL 体系中的优越的 TTA-UC 具有相对较高的三重态扩散常数（1.63×10(-6) cm(2) s(-1))，这归因于 IL 中存在离子发色团网络。
