High-resolution Performance of Leaning Pillar[6]arene Functionalized with Imidazolium Ionic Liquids for Gas Chromatography

Leaning pillar[6]arene (LP6A) is an expanded version of pillar[6]arene (P6A), possessing not only the nanometer-sized cavity of P6A but also a unique desymmetrized leaning tower-like structure, which offers better structural flexibility and cavity adaptability. Here we report the first example of the utilization of imidazolium ionic liquid (IMIL) functionalized LP6A (LP6A-C10-IM-C8[NTf 2 ]) as a stationary phase in capillary gas chromatography (GC). The LP6A-C10-IM-C8[NTf 2 ] capillary column was prepared by the static coating method, showing medium polarity (average polarity 155) and high column efficiency (3758 plates/m). Using long alkyl chains modified LP6A (LP6A-C10) as a reference column, its retention behaviour and resolving performance were elucidated by a mixture of 30 analytes. Importantly, the LP6A-C10-IM-C8[NTf 2 ] column exhibited advantageous separation performance for the challenging isomers of halogenated benzenes, benzaldehydes, phenols, and anilines over the LP6A-C10 and commercial HP-5, HP-35, and DB-17 columns. In addition, the LP6A-C10-IM-C8[NTf 2 ] column has been used to determine the purity of isomer impurities in actual samples, demonstrating good potential in GC separations. Graphical This work reported the first example of utilization of imidazolium ionic liquid (IMIL) functionalized leaning pillar[6]arene (LP6A-C10-IM-C8[NTf 2 ]) as a stationary phase in capillary gas chromatography separations and obtained a high resolution performance for multiple anayltes.