Time-efficient synthetic methods of porous organic polymers are searched in order to extend the applications of these materials. In this work, we show a robust and time-efficient synthetic method of azo-linked porous organic polymers named Azo-POPs based on a NaBH₄-mediated reductive coupling polymerization on well-known polynitro monomers. Azo-POPs were found to have a high Brunauer–Emmett–Teller (BET) surface area and potential for aniline adsorption. Interestingly, Azo-POP-1 showed adsorption capacity towards aniline as high as 1059.68 mg g⁻¹ at 293 K, which surpassed that of adsorbent materials reported in the literature.

A nitro group functionalized porous aromatic framework (NO₂-PAF-1) was synthesized via a copper-mediated Ullmann reaction. Its CO₂ uptake was higher that of PAF-1 due to the strong interaction of the nitro group with CO₂.

Functional porous organic polymers (POPs) such as PIM-1 with good solubility have been used for the homogenization of heterogeneous catalysts very recently, in addition to the traditional gas/liquid adsorption and separation. As emerging functional POPs, Azo-POPs have been studied broadly, although they are usually insoluble. This paper reports a novel soluble Azo-POP (named Azo-POP-7) with a fluorene-derived β-hydroxy-azobenzene subunit in the polymer main chain for the first time via a facile azo-coupling polymerization of contorted monomers. The resultant polymers exhibited a Brunauer–Emmett–Teller (BET) specific surface area of 364 m² g⁻¹ and good solubility in most organic solvents. Moreover, the soluble catalyst Pd@Azo-POP-7 showed the highest efficiency (k_app = 4.95 × 10⁻² s⁻¹) for the organic-aqueous biphasic reduction reaction of 4-nitrophenol with good recyclability (12 cycles). This work introduces a novel strategy for designing novel functional POPs for organic/aqueous biphasic catalysis.