Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
Nat Chem. 2017 Jun;9(6):563-570. doi: 10.1038/nchem.2696. Epub 2017 Jan 16.
The fabrication of crystalline 2D conjugated polymers with well-defined repeating units and in-built porosity presents a significant challenge to synthetic chemists. Yet they present an appealing target because of their desirable physical and electronic properties. Here we report the preparation of a 2D conjugated aromatic polymer synthesized via C-C coupling reactions between tetrabromopolyaromatic monomers. Pre-arranged monomers in the bulk crystal undergo C-C coupling driven by endogenous solid-state polymerization to produce a crystalline polymer, which can be mechanically exfoliated into micrometre-sized lamellar sheets with a thickness of 1 nm. Isothermal gas-sorption measurements of the bulk material reveal a dominant pore size of ~0.6 nm, which indicates uniform open channels from the eclipsed stacking of the sheets. When employed as an organic anode in an ambient-temperature sodium cell, the material allows a fast charge/discharge of sodium ions, with impressive reversible capacity, rate capability and stability metrics.
具有明确重复单元和内置孔隙的结晶二维共轭聚合物的制备对合成化学家来说是一个重大挑战。然而，由于它们具有理想的物理和电子特性，因此它们是一个吸引人的目标。在这里，我们报告了通过在四溴聚芳烃单体之间的 C-C 偶联反应合成二维共轭芳香族聚合物的制备。在块状晶体中预先排列的单体在固体内源聚合的驱动下进行 C-C 偶联，生成结晶聚合物，该聚合物可以机械剥离成厚度为 1nm 的微米级层状薄片。对块状材料的等温气体吸附测量表明，主要孔径约为 0.6nm，这表明从薄片的重叠堆积中形成均匀的开放通道。当将该材料用作环境温度钠电池中的有机阳极时，该材料允许钠离子快速充放电，并具有令人印象深刻的可逆容量、倍率性能和稳定性指标。
