Two porphyrin-based porous polyimide polymers, PPPP-1 and PPPP-2, were synthesized via 4 + 2 polyimide reactions of extended porphyrin tetraamines (TBPP) and pyromellitic dianhydride (PMDA), or naphthalene dianhydride (NTDA). The polyimide structures were unambiguously confirmed by FT-IR and ¹³C CP-MAS solid state NMR. Powder X-ray diffraction and computer modeling analysis confirmed the crystallinity and the layered structures with tetragonal channels of PPPP-1 and PPPP-2. The Brunauer–Emmett–Teller (BET) surface area together with pore size distribution suggested permanent porosity, whose surface areas were calculated as 295.07 m² g⁻¹ and 301.48 m² g⁻¹ for PPPP-1 and PPPP-2, respectively. Furthermore, the morphology of PPPPs was confirmed by exhaustive scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging. Highly dispersed Pd nanoparticles with a diameter of 3 ± 2 nm were successfully immobilized into PPPPs through the coordination of Pd(II) ions with porphyrin units on polymers and in situ reduction afterwards. Pd@PPPP-1 and Pd@PPPP-2 show significantly excellent catalytic activity in Suzuki–Miyaura coupling reactions. The performance of Pd@PPPPs is apparently superior to that of the homogeneous palladium catalyst. In addition, Pd@PPPPs have excellent stability and recyclability, and they can be reused without loss of activity in five successive reaction cycles. These results indicate that the polyimide porphyrin porous organic polymers are promising candidates for efficient heterogeneous catalysis.

中文翻译：

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卟啉基多孔聚酰亚胺聚合物/ Pd纳米颗粒复合材料可作为Suzuki-Miyaura偶联反应的有效催化剂†

通过扩展卟啉四胺（TBPP）和均苯四甲酸二酐（PMDA）或萘二酐（NTDA）的4 + 2聚酰亚胺反应合成了两种基于卟啉的多孔聚酰亚胺聚合物PPPP-1和PPPP-2。FT-IR和¹³ C CP-MAS固态NMR明确证实了聚酰亚胺的结构。粉末X射线衍射和计算机建模分析证实了PPPP-1和PPPP-2的结晶性和具有四方通道的层状结构。Brunauer-Emmett-Teller（BET）表面积以及孔径分布表明存在永久孔隙，其表面积经计算为295.07 m ² g ^-1对于PPPP-1和PPPP-2分别为301.48 m ² g ^-1。此外，通过穷举扫描电子显微镜（SEM）和透射电子显微镜（TEM）成像证实了PPPPs的形态。通过将Pd（II）离子与卟啉单元配位到聚合物上，然后原位还原，将直径3±2 nm的高度分散的Pd纳米颗粒成功地固定在PPPPs中。Pd @ PPPP-1和Pd @ PPPP-2在Suzuki-Miyaura偶联反应中显示出显着优异的催化活性。Pd @ PPPPs的性能明显优于均相钯催化剂。此外，Pd @ PPPP具有出色的稳定性和可回收性，并且可以在五个连续的反应周期中重复使用而不会失去活性。这些结果表明，聚酰亚胺卟啉多孔有机聚合物是有效的多相催化的有希望的候选者。