Chen Shun-Li, Zhang Meng-Meng, Chen Jiecheng, Wen Xinyi, Chen Wenbin, Li Jiayu, Chen Ye-Tao, Xiao Yonghong, Liu Huifen, Tan Qianqian, Zhu Tangjun, Ye Bowei, Yan Jiajun, Huang Yihang, Li Jie, Ni Shaofei, Dang Li, Li Ming-De
College of Chemistry and Chemical Engineering, and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou, 515063, P. R. China.
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
ChemSusChem. 2023 Jul 21;16(14):e202300644. doi: 10.1002/cssc.202300644. Epub 2023 Jun 29.
Inspired by the concept of ionic charge-transfer complexes for the Mott insulator, integer-charge-transfer (integer-CT) cocrystals are designed for NIR photo-thermal conversion (PTC). With amino-styryl-pyridinium dyes and F4TCNQ (7,7',8,8'-Tetracyano-2,3,5,6-tetrafluoroquinodimethane) serving as donor/acceptor (D/A) units, integer-CT cocrystals, including amorphous stacking "salt" and segregated stacking "ionic crystal", are synthesized by mechanochemistry and solution method, respectively. Surprisingly, the integer-CT cocrystals are self-assembled only through multiple D-A hydrogen bonds (C-H⋅⋅⋅X (X=N, F)). Strong charge-transfer interactions in cocrystals contribute to the strong light-harvesting ability at 200-1500 nm. Under 808 nm laser illumination, both the "salt" and "ionic crystal" display excellent PTC efficiency beneficial from ultrafast (∼2 ps) nonradiative decay of excited states. Thus integer-CT cocrystals are potential candidates for rapid, efficient, and scalable PTC platforms. Especially amorphous "salt" with good photo/thermal stability is highly desirable in practical large-scale solar-harvesting/conversion applications in water environment. This work verifies the validity of the integer-CT cocrystal strategy, and charts a promising path to synthesize amorphous PTC materials by mechanochemical method in one-step.
受莫特绝缘体离子电荷转移络合物概念的启发，设计了用于近红外光热转换（PTC）的整数电荷转移（整数-CT）共晶体。以氨基苯乙烯基吡啶鎓染料和F4TCNQ（7,7',8,8'-四氰基-2,3,5,6-四氟喹二甲烷）作为供体/受体（D/A）单元，分别通过机械化学法和溶液法合成了包括无定形堆积“盐”和分离堆积“离子晶体”的整数-CT共晶体。令人惊讶的是，整数-CT共晶体仅通过多个D-A氢键（C-H⋅⋅⋅X（X = N，F））自组装而成。共晶体中强烈的电荷转移相互作用有助于在200-1500 nm处具有很强的光捕获能力。在808 nm激光照射下，“盐”和“离子晶体”均显示出优异的PTC效率，这得益于激发态的超快（~2 ps）非辐射衰减。因此，整数-CT共晶体是快速、高效和可扩展的PTC平台的潜在候选材料。特别是具有良好光/热稳定性的无定形“盐”在水环境中的实际大规模太阳能收集/转换应用中非常理想。这项工作验证了整数-CT共晶体策略的有效性，并为通过机械化学方法一步合成无定形PTC材料开辟了一条有前景的道路。
