Hamzehpoor Ehsan, Ghamari Pegah, Tao Yuze, Rafique Muhammad Ghufran, Zhang Zhenzhe, Salehi Mahdi, Stein Robin S, Ramos-Sanchez Jorge, Laramée Arnaud W, Cosa Gonzalo, Pellerin Christian, Seifitokaldani Ali, Khaliullin Rustam Z, Perepichka Dmytro F
Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 09B, Canada.
Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, Quebec, H3A 0C5, Canada.
Adv Mater. 2024 Dec;36(50):e2413629. doi: 10.1002/adma.202413629. Epub 2024 Oct 21.
Two near-infrared (NIR) emissive π-conjugated covalent organic frameworks (COFs) pTANG1 and pTANG2 are synthesized using Knoevenagel condensation of trioxaazatriangulenetricarbaldehyde (TATANG) with benzene- and biphenyldiacetonitriles, respectively. The morphology of the COFs is affected by the size of TATANG precursor crystals. Donor-acceptor interactions in these COFs result in small bandgaps (≈1.6 eV) and NIR emission (λ = 789 nm for pTANG1). pTANG1 can absorb up to 9 molecules of water per unit cell, which is accompanied by a marked quenching of the NIR emission, suggesting applications as humidity sensors. p-Doping with magic blue significantly increases the electrical conductivities of the COFs by up to 8 orders of magnitude, with the room temperature conductivity of pTANG1 reaching 0.65 S cm, the highest among reported C═C linked COFs. H NMR relaxometry, temperature-dependent fluorescence spectroscopy, and DFT calculations reveal that the higher rigidity of the shorter phenylene linker is responsible for the more extended conjugation (red-shifted emission, higher electrical conductivity) of pTANG1 compared to pTANG2.
分别使用三氧杂氮杂三蝶烯三甲醛（TATANG）与苯二乙腈和联苯二乙腈通过克诺文纳格尔缩合反应合成了两种近红外（NIR）发射型π共轭共价有机框架（COF），即pTANG1和pTANG2。COF的形态受TATANG前体晶体尺寸的影响。这些COF中的供体-受体相互作用导致小的带隙（≈1.6 eV）和近红外发射（pTANG1的λ = 789 nm）。pTANG1每个晶胞最多可吸收9个水分子，这伴随着近红外发射的显著猝灭，表明其可作为湿度传感器应用。用魔蓝进行p型掺杂可使COF的电导率显著提高多达8个数量级，pTANG1的室温电导率达到0.65 S/cm，是已报道的C═C连接的COF中最高的。1H NMR弛豫测量、变温荧光光谱和密度泛函理论计算表明，与pTANG2相比，较短亚苯基连接体更高的刚性是pTANG1具有更广泛共轭（发射红移、电导率更高）的原因。
