Kumar Yogesh, Gupta Sandeep, Nandi Shyamapada, Kumar Arun, Mohanty Paritosh, Pandey Ravindra
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
Department of Chemistry, Vellore Institute of Technology, Chennai, 600127, India.
Mater Horiz. 2025 Sep 2. doi: 10.1039/d5mh01125f.
Covalent organic frameworks (COFs) are emerging as promising materials across diverse fields, including catalysis, gas storage, water harvesting, and energy storage. Traditionally, COF development relies on the two-component synthesis approach, where two organic monomers with specific reactive sites are strategically combined to form well-ordered frameworks in specific topologies. Although this approach has been effective, it inherently restricts the structural diversity of COFs unless new linkers are introduced, limiting the range of properties achievable. A more flexible and increasingly popular approach in COF synthesis is the use of multicomponent reactions and mixed linker strategies, incorporating three or more organic monomers into a single COF. While researchers have primarily focused on reaction pathways for synthesizing multiple-component COFs, one area that remains relatively underexplored is the use of flexible linkers within these strategies. This study addresses this gap by selecting a flexible amine linker and combining it with four distinct aldehyde linkers in various combinations. This approach allows us to successfully synthesize fifteen different highly crystalline COF materials, including two-component, along with three, four, and five-component COFs. A comparative study of photocatalytic performance between the two-component with the five-component COF demonstrated that increased structural functionalities leads to higher surface area, enhanced visible-light absorption, and consequently enhanced photocatalytic activity in the oxidative conversion of aryl phenylboronic acid to phenol.
共价有机框架（COF）正在成为各个领域中颇具前景的材料，包括催化、气体存储、集水和能量存储。传统上，COF的开发依赖于双组分合成方法，即具有特定反应位点的两种有机单体经过精心组合，形成具有特定拓扑结构的有序框架。尽管这种方法很有效，但它本质上限制了COF的结构多样性，除非引入新的连接体，这就限制了可实现的性能范围。在COF合成中，一种更灵活且越来越流行的方法是使用多组分反应和混合连接体策略，即将三种或更多种有机单体纳入单个COF中。虽然研究人员主要关注合成多组分COF的反应途径，但在这些策略中，一个相对未被充分探索的领域是使用柔性连接体。本研究通过选择一种柔性胺连接体，并将其与四种不同的醛连接体以各种组合方式相结合，填补了这一空白。这种方法使我们成功合成了十五种不同的高度结晶的COF材料，包括双组分以及三组分、四组分和五组分的COF。对双组分和五组分COF的光催化性能进行的比较研究表明，结构功能的增加会导致更高的表面积、增强的可见光吸收，从而在芳基苯硼酸氧化转化为苯酚的过程中增强光催化活性。
