Synthesis and Properties of Conjugated Microporous Polymers Bearing Pyrazine Moieties with Macroscopically Porous 3D Networks Structures

The N‐containing conjugated microporous polymers (CMPs) are synthesized by 2,5‐dibromopyrazine or its isomeric pyridazine monomer and 1,3,5‐triethynylbenzene via the Pd(0)/Cu(I)‐catalyzed Sonogashira–Hagihara cross‐coupling polycondensation. The resulting CMPs exhibit diverse porosity and morphology, which reveals macroscopically porous 3D networks for BQCMP‐1, agglomerated and amorphous structure for DQCMP‐1, arising from the variation of isomeric monomer. In addition, metal ions adsorption capacity of Zn(II), Cr(VI), Ni(II) have been investigated due to the good porosity of CMPs. Compared with Zn(II) and Cr(VI), the adsorption capacity of Ni(II) for BQCMP‐1 and DQCMP‐1 is maximal, which is 272 mg g−1 and 559 mg g−1. Our study may provide a useful guidance to manipulate CMPs by varying the constitution of isomeric monomer. The N‐containing conjugated microporous polymers (CMPs) are synthesized using palladium‐catalyzed Sonogashira–Hagihara cross‐coupling of 1,3,5‐trethynylbenze with 2,5‐dibromopyrazine or its isomeric pyridazine monomer at a 1.5:1 molar ratio of ethynyl to bromo functionalities with toluene as a solvent. The resulting CMPs exhibit macroscopically porous 3D networks and show a good performance for heavy metal ions adsorption.