Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Science (ICCAS), Beijing, 100190, China.
Angew Chem Int Ed Engl. 2018 Apr 3;57(15):3963-3967. doi: 10.1002/anie.201712949. Epub 2018 Mar 8.
A cocrystal strategy with a simple preparation process is developed to prepare novel materials for near-infrared photothermal (PT) conversion and imaging. DBTTF and TCNB are selected as electron donor (D) and electron acceptor (A) to self-assemble into new cocrystals through non-covalent interactions. The strong D-A interaction leads to a narrow band gap with NIR absorption and that both the ground state and lowest-lying excited state are charge transfer states. Under the NIR laser illumination, the temperature of the cocrystal sharply increases in a short time with high PT conversion efficiency (η=18.8 %), which is due to the active non-radiative pathways and inhibition of radiative transition process, as revealed by femtosecond transient absorption spectroscopy. This is the first PT conversion cocrystal, which not only provides insights for the development of novel PT materials, but also paves the way of designing functional materials with appealing applications.
一种具有简单制备工艺的共晶策略被开发出来，用于制备用于近红外光热（PT）转换和成像的新型材料。DBTTF 和 TCNB 被选择为电子给体（D）和电子受体（A），通过非共价相互作用自组装成新的共晶。强的 D-A 相互作用导致具有近红外吸收的窄带隙，并且基态和最低激发态都是电荷转移态。在近红外激光照射下，共晶的温度在短时间内急剧升高，具有高的 PT 转换效率（η=18.8%），这归因于飞秒瞬态吸收光谱所揭示的活性非辐射途径和辐射跃迁过程的抑制。这是第一个 PT 转换共晶，它不仅为开发新型 PT 材料提供了思路，而且为设计具有吸引力应用的功能材料铺平了道路。
