Yang Shuailong, Chen Ziao, Zou Lei, Cao Rong
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China.
Adv Sci (Weinh). 2023 Nov;10(31):e2304697. doi: 10.1002/advs.202304697. Epub 2023 Sep 20.
The establishment of facile synthetic routes to engineer covalent organic frameworks (COFs) with fully conjugated structure and excellent stability is highly desired for practical applications in optoelectronics and photocatalysis. Herein, a novel linkage conversion strategy is reported to prepare crystalline thiadiazole-linked COFs via thionation, cyclization, and oxidation of N-acylhydrazole bonds with Lawesson's reagent (LR). The as-prepared thiadiazole-linked COFs not only remain porosity and crystallinity, but enhance its chemical stability. Furthermore, thiadiazole-linked COFs are more favorable to lower exciton binding energy and promote π-electron delocalization over the whole reticular framework than N-acylhydrazone-linked COFs. Notably, the extended π-conjugation structure and decent crystallinity of the resulting TDA-COF are reflected by its higher photocatalytic H evolution rate (61.3 mmol g in 5 h) in comparison with that (7.5 mmol g ) of NAH-COF.
开发简便的合成路线来构建具有完全共轭结构和优异稳定性的共价有机框架（COF）对于其在光电子学和光催化领域的实际应用至关重要。在此，我们报道了一种新颖的连接转化策略，通过用劳森试剂（LR）对N-酰基肼键进行硫代、环化和氧化反应，制备结晶噻二唑连接的COF。所制备的噻二唑连接的COF不仅保留了孔隙率和结晶度，还提高了其化学稳定性。此外，与N-酰腙连接的COF相比，噻二唑连接的COF更有利于降低激子结合能，并促进整个网状框架上的π电子离域。值得注意的是，与NAH-COF（7.5 mmol g）相比，所得TDA-COF更高的光催化析氢速率（5小时内61.3 mmol g）反映了其扩展的π共轭结构和良好的结晶度。
