Room temperature synthesis of a chiral covalent organic framework core-shell composite for high-performance liquid chromatography enantioseparation

Abstract

In this article, chiral covalent organic framework core-shell composite CCOF-TpPa-Py@SiO₂ was facilely synthesized by induction at room temperature. The CCOF-TpPa-Py@SiO₂ core-shell composite was used as a chiral stationary phase for the separation of the racemates by high-performance liquid chromatography, which exhibits good separation performance for chiral compounds including ketones, alcohols, esters, epoxides, carboxylic acids, amides, and amines. The effects of analyte injection mass on the enantioseparation were studied. The reproducibility and stability of the CCOF-TpPa-Py@SiO₂ chiral column were explored. The intra-day (n = 5), inter-day (n = 5), and inter-column (n = 3) relative standard deviations for the migration times and resolution of benzoin were 0.32%–0.54%, 0.45%–0.61%, and 1.21%–1.53%, respectively. In addition, the chiral separation ability of the CCOF-TpPa-Py@SiO₂ chiral column (column A) was compared with that of the MDI-β-CD-Modified COF@SiO₂ (column B) as well as a commercial chiral column (Chiralpak AD-H). The chiral recognition ability of column A is complementary to that of column B and AD-H column. The resolution mechanism of CCOF-TpPa-Py@SiO₂ stationary phase towards chiral analyte was explored. Hence, the synthesis of CCOF-TpPa-Py@SiO₂ core-shell composite by induction at room temperature as chiral stationary phases for chromatographic separation has important research potential and application prospects.