One‐pot synthesis of pillar[5]quinone‐amine polymer coated silica as stationary phase for high‐performance liquid chromatography

To expand the application of pillararene in chromatographic separation, we designed and fabricated a pillar[5]quinone‐amine polymer coated silica through quinone‐amine reaction by facile one‐pot synthesis method, which was applied as a stationary phase for high‐performance liquid chromatography. Separation of hydrophobic compounds, hydrophilic compounds, halogenated aromatic compounds, and 11 aromatic positional isomers was achieved successfully in this stationary phase. Reverse‐phase separation mode and hydrophilic‐interaction separation mode were proved to exist, indicating the potential application of the mix‐mode stationary phase. Studies of chromatographic retention behavior and molecular simulation showed that multiple interactions might play an important role in the separation process, including hydrophobic interaction, hydrogen‐bonding interaction, aromatic π‐π interaction, electron donor‐acceptor interaction, and host‐guest interaction. Column repeatability and stability were tested, which showed relative standard deviations of retention time less than 0.2% for continuous 11 injections, and the durability relative standard deviations of retention time were less than 0.91% after 90 days. This novel design strategy would broaden the application of pillararene‐based covalent organic polymer in chromatography and separation science.