共价有机框架(COFs)是巨大的兴趣,因为它们的潜在应用跨越不同的领域,如气体储存和分离,催化作用,药物输送系统,传感,有机电子。鉴于他们面向应用的追求,电致变色领域标志着2019年第一个电致变色COF的报告取得了重大进展[J.Am.Chem.Soc.2019、141、19831-19838]。从那以后,具有电致变色特征的新的和新颖的COF结构(表示为ecCOF)已经被不断地搜索。然而,迄今为止,仅建造了少数ecCOF。仔细观察这些报道表明,COF组件中的多电致变色(显示至少三种氧化还原颜色状态)仅实现了一次,通过三态电致变色[Angew。Chem.2021,133,12606-1261]。在这里,我们报告了通过无金属催化剂的席夫碱方法构建的基于三(4-氨基苯基)胺-对苯二甲醛(TAPA-PDA)的COF中的四态电致变色。四州(橙色,梨,绿色,和青色)由TAPA-PDAecCOF证明的电致变色为ecCOF在触发器逻辑门中的最终用途开辟了几种未来途径,智能窗户,装饰性展示,和节能装置。
Covalent organic frameworks (COFs) are of massive interest due to their potential application spanning diverse fields such as gas storage and separation, catalysis, drug delivery systems, sensing, and organic electronics. In view of their application-oriented quest, the field of electrochromism marked a significant stride with the reporting of the first electrochromic COF in 2019 [J. Am. Chem. Soc. 2019, 141, 19831-19838]. Since then, new and novel COF structures with electrochromic features (denoted as ecCOFs) have been searched continuously. Yet, only a handful of ecCOFs have been constructed to date. A closer look at these reports suggests that multielectrochromism (showing at least three redox color states) in a COF assembly has only been achieved once, manifested through three-state electrochromism [Angew. Chem. 2021, 133, 12606 - 1261]. Herein, we report four-state electrochromism in tris(4-aminophenyl)amine-terephthalaldehyde (TAPA-PDA)-based COF constructed through the metal-catalyst free Schiff base approach. The four-state (orange, pear, green, and cyan) electrochromism demonstrated by the TAPA-PDA ecCOF opens several futuristic avenues for ecCOF\'s end use in flip-flop logic gates, intelligent windows, decorative displays, and energy-saving devices.