Chiral Covalent Organic Framework Composite CCOF-301@SiO₂ for Multi-Mode HPLC Enantiomeric Separation

Area of Science:

• Materials Science
• Analytical Chemistry
• Organic Chemistry

Background:

• Chiral covalent organic frameworks (CCOFs) possess unique structures and abundant chiral recognition sites, making them promising for chromatographic separations.
• Developing efficient chiral stationary phases (CSPs) is crucial for resolving enantiomers in high-performance liquid chromatography (HPLC).

Purpose of the Study:

• To synthesize a novel CCOF core-shell composite, CCOF-301@SiO2, using post-synthesis modification and in-situ growth.
• To evaluate the efficacy of the CCOF-301@SiO2 composite as a multifunctional CSP for enantiomeric separation in both normal-phase (NP) and reversed-phase (RP) HPLC.
• To investigate the influence of acetic acid catalyst concentration on the synthesis of CCOF-301@SiO2 core-shell microspheres.

Main Methods:

• Construction of CCOF-301@SiO2 core-shell microspheres via post-synthesis modification and in-situ growth strategies.
• Utilizing the prepared CCOF-301@SiO2 composite as a CSP in HPLC for enantiomeric separation.
• Investigating the effects of catalyst amount, analyte mass, column temperature, and mobile phase composition on separation performance.

Main Results:

• The CCOF-301@SiO2 column demonstrated excellent separation performance, successfully resolving 20 chiral compounds in NP mode and 12 in RP mode, including alcohols, esters, ketones, and amines.
• The CCOF-301@SiO2 column exhibited good complementarity compared to a commercial Chiralpak AD-H column.
• The column showed good repeatability and stability for enantioseparation tasks.

Conclusions:

• CCOF-301@SiO2 core-shell composites synthesized via PSM and in-situ growth are highly effective as HPLC stationary phases.
• The developed CCOFs@SiO2 material shows significant potential for advanced enantiomeric separations in chromatography.
• Optimization of synthesis conditions, such as acetic acid catalyst amount, is important for achieving desired CCOF-301@SiO2 microsphere properties.