Yuan Zhiyi, Zou Lei, Chang Dongdong, Ma Xiang
Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
ACS Appl Mater Interfaces. 2020 Nov 18;12(46):52059-52069. doi: 10.1021/acsami.0c17119. Epub 2020 Nov 9.
Amorphous organic room-temperature phosphorescent (RTP) materials are promising for their facile preparation and processability, while the conformation effects of phosphors at amorphous state are lack of study in comparison with the rigid effects due to the commonly irregular assembling and dispersal of phosphors in rigid systems. Herein, we report a series of phosphorescent molecules modified by polyhydroxy galactose, whose RTP emission at the amorphous state can be regulated by controlling the conformational distortion of the phosphorescent segments. Further, a strong RTP emission is facilely obtained by the co-assembling between polyhydroxy phosphors and polyhydroxy matrices (α-CD, β-CD, and chitosan). Owing to the rigid effect of the enhanced hydrogen bonding cross-linking, the highest RTP quantum yield reaches 19.4%; whereas, the RTP emissions of assemblies become conformation insensitive. The conflicting relationship between the conformation effect and rigid effect is attributed to the differences between aggregated single-component systems and dispersed assembling systems. Besides, the unique and different moisture responsiveness of the co-assembling samples is discovered and further applied in data encryption. The research expands the scope for designing amorphous pure organic RTP materials with supramolecular strategies and shows a modularized approach for assembling-enhanced phosphorescence.
非晶态有机室温磷光（RTP）材料因其易于制备和加工而颇具前景，然而，与刚性体系中磷光体通常不规则的组装和分散所导致的刚性效应相比，非晶态下磷光体的构象效应缺乏研究。在此，我们报道了一系列由多羟基半乳糖修饰的磷光分子，其在非晶态下的RTP发射可通过控制磷光片段的构象畸变来调节。此外，通过多羟基磷光体与多羟基基质（α-环糊精、β-环糊精和壳聚糖）之间的共组装，可轻松获得强烈的RTP发射。由于增强的氢键交联的刚性效应，最高RTP量子产率达到19.4%；而组装体的RTP发射对构象不敏感。构象效应与刚性效应之间的矛盾关系归因于聚集的单组分体系和分散的组装体系之间的差异。此外，还发现了共组装样品独特且不同的湿度响应性，并将其进一步应用于数据加密。该研究扩展了用超分子策略设计非晶态纯有机RTP材料的范围，并展示了一种用于组装增强磷光的模块化方法。
