中科院宁波材料科学技术与工程研究所张涛团队报道了直接构建具有独特光催化性能的苯并双恶唑-乙烯基连接的共价有机框架。相关研究成果发表在2022年7月25日出版的《美国化学会杂志》。

乙烯/烯烃连接的二维共价有机框架（v-2D-COFs）是一种先进的半导体材料，具有良好的面内共轭、高化学稳定性和精确可调的电子结构。探索v-2D-COFs网状结构的新连接化学仍处于起步阶段，具有挑战性。

该文中，研究人员提出了一种固态苯并双恶唑介导的羟醛缩聚反应，用于构建两种具有苯并双恶唑反式和顺式构型的新型异构苯并双恶唑桥联v-2D-COFs（v-2D-COF-NO1和v-2D-COF-NO2）。有趣的是，苯并双恶唑异构体使两种v-2D-COFs具有不同的光电和电化学特性，从光吸收和发射到电荷转移特性。当用作光电阴极时，v-2D-COF-NO1在0.3 V AM 1.5G辐照下与可逆氢电极（RHE）相比，表现出高达～18μA/cm²的光电流，是v-2D-COF-NO2值的两倍（～9.1μA/cm²）。以铂为助催化剂，v-2D-COF-NO1的光催化析氢速率约为1.97 mmol h^–1 g^–1，与相同条件下的v-2D-COF-NO2（～0.86 mmol h^–1 g^–1）形成鲜明对比。

该研究证明了通过苯并双恶唑介导的羟醛缩聚反应合成具有异构结构和独特光催化性能的v-2D-COFs。

附：英文原文

Title: Direct Construction of Isomeric Benzobisoxazole–Vinylene-Linked Covalent Organic Frameworks with Distinct Photocatalytic Properties

Author: Shengxu Li, Rui Ma, Shunqi Xu, Tianyue Zheng, Guangen Fu, Yanling Wu, Zhongquan Liao, Yongbo Kuang, Yang Hou, Dashuai Wang, Petko Stoev Petkov, Kristina Simeonova, Xinliang Feng, Li-Zhu Wu, Xu-Bing Li, Tao Zhang

Issue&Volume: July 25, 2022

Abstract: Vinylene/olefin-linked two-dimensional covalent organic frameworks (v-2D-COFs) have emerged as advanced semiconducting materials with excellent in-plane conjugation, high chemical stabilities, and precisely tunable electronic structures. Exploring new linkage chemistry for the reticular construction of v-2D-COFs remains in infancy and challenging. Herein, we present a solid-state benzobisoxazole-mediated aldol polycondensation reaction for the construction of two novel isomeric benzobisoxazole-bridged v-2D-COFs (v-2D-COF-NO1 and v-2D-COF-NO2) with trans and cis configurations of benzobisoxazole. Interestingly, the isomeric benzobisoxazole linkers endow the two v-2D-COFs with distinct optoelectronic and electrochemical properties, ranging from light absorption and emission to charge-transfer properties. When employed as the photocathode, v-2D-COF-NO1 exhibits a photocurrent of up to ～18 μA/cm2 under AM 1.5G irradiation at 0.3 V vs reversible hydrogen electrode (RHE), which is twice the value of v-2D-COF-NO2 (～9.1 μA/cm2). With Pt as a cocatalyst, v-2D-COF-NO1 demonstrates a photocatalytic hydrogen evolution rate of ～1.97 mmol h–1 g–1, also in clear contrast to that of v-2D-COF-NO2 (～0.86 mmol h–1 g–1) under identical conditions. This work demonstrates the synthesis of v-2D-COFs via benzobisoxazole-mediated aldol polycondensation with isomeric structures and distinct photocatalytic properties.

DOI: 10.1021/jacs.2c06042

Source: https://pubs.acs.org/doi/10.1021/jacs.2c06042