本文要点：
Friedel-Crafts反应因其操作简单、结构单元丰富而被广泛应用于多种多孔有机聚合物的制备。然而，由于其不可逆和过多的随机反应位点，通过Friedel-Crafts反应合成结晶有机聚合物/骨架至今尚未实现。
在本文中，作者开发了一种分子受限的Friedel-Crafts反应策略，首次实现了具有可定制功能的高度结晶共价三嗪框架(CTFs)的快速制备(仅在30分钟内)。
理论计算和详细的实验揭示了芳香苯单体中的羧基在CTFs结晶过程中的关键作用，它不仅可以通过其吸电子性质有效地为2,4,6-三氯-1,3,5-三嗪的亲电攻击提供合适的活化势垒，还可以引入锚定效应(分子限制效应)以促进2D平面方向特定位点的有序聚合。
得益于便捷的合成路线和低成本的原料，前所未有地实现了羧基功能化高结晶度CTFs的公斤级制备。此外，由于羧基的亲水性和可离子化性质，所得官能化CTFs表现出优异的水分散性和优异的溶液加工性。
Figure 1. (a) Previously reported synthetic strategies for CTFs. (b) Schematic diagram for synthesizing CTF-2COOH and CTF-3COOH.
Figure 2. (a, c) PXRD patterns of CTF-2COOH and CTF-3COOH. (b) Nitrogen adsorption-desorption isotherms of CTF-2COOH. Insets show its pore-size distributions. (d) FTIR spectra of CTF-2COOH and CTF-3COOH and their corresponding monomers. (e) 13C CP/MAS spectra of CTF-2COOH and CTF-3COOH. (f) XPS O 1s and C 1s spectra of CTF-2COOH and CTF-3COOH. (g) Photograph of kilogramscale preparation of CTF-2COOH. (h) PXRD pattern of kilogram-scale CTF-2COOH.
Figure 3. (a) SEM images of CTF-2COOH. The inset displays local enlarged area. (b) TEM images of CTF-2COOH nanosheets. Insets show photographs of the corresponding Tyndall effect of CTF-2COOH aqueous dispersions. (c) AFM images of CTF-2COOH nanosheets. (d) The HRTEM image of CTF-2COOH nanosheets. Insets show the FFT patterns from the white square marked area. (e) The local enlargement of the white square marked area in the d-graph. (f) TEM-EDX mapping of CTF-2COOH nanosheets.
Figure 4. (a) Schematic diagram of ordered 2D polymerization mechanism. (b) Time-dependent PXRD patterns of CTF-2COOH. (c) PXRD spectra of comparative experiments. (d) Photograph of comparative experiments for electron-withdrawing group effect. (e) Reaction coordinate via DFT calculation in the model Friedel-Crafts reaction of PTA monomer catalyzed by CF3SO3H. (f) Reaction coordinate via DFT calculation in the model Friedel-Crafts reaction of DMB monomer catalyzed by CF3SO3H. (g) DFT-optimized geometric structures of the model Friedel-Crafts reaction of PTA monomer catalyzed by CF3SO3H.
Figure 5. (a) PXRD pattern of the crystalline CTF-2COONa nanoparticles. The inset represents the photograph of the bulk CTF-2COOH and the corresponding exfoliated CTF-2COONa nanoparticles. (b) Nitrogen adsorption-desorption isotherms of crystalline CTF-2COONa nanoparticles. Inset shows its pore-size distributions. (c) Scalable preparation of aqueous dispersion of CTF-2COONa nanoparticles (10 L, ~1 mg mL−1). (d) PXRD pattern of flexible PVA/CTFs MMMs with 60 wt% CTFs loading. Inset shows the flexibility of the PVA/CTFs MMMs.
https://doi.org/10.1002/anie.202421251
