Benzimidazole‐Linked Porous Polymers: Synthesis and Gas Sorption Properties

A series of benzimidazole‐linked porous polymers are obtained by the condensation reaction between the o‐aminobenzol end groups of building blocks (2,3,6,7,10,11‐hexaaminotriphenylene, 3,3′‐diaminobenzidine or 1,2,4,5‐benzenetetraamine) and the aldehyde groups of building blocks [terephthalicaldehyde, 4,4′‐biphenyldicarboxaldehyde, 1,3,5‐tris(4‐acetylphenyl)benzene or 1,3,5‐tris(4‐formylbiphenyl)amine] in one‐pot synthesis without employing any catalyst or template. The existence of the imidazole ring in the obtained polymers could be identified by Fourier transform infrared and solid‐state 13C CP/MAS NMR spectroscopy. The sphere‐shaped morphology of the obtained polymers is observed through scanning electron microscopy. The polymers possess Brunauer‐Emmett‐Teller specific surface area values over 600 m2·g−1, showing hydrogen storage (up to 1.6 wt%, at 77 K and 1×105 Pa) and carbon dioxide capture (up to 12.6 wt%, at 273 K and 1×105 Pa) properties. Such polymers would possess good performance in the applications of gas storage and separation.