Facile preparation of fluorine-functionalized covalent organic frameworks@SiO2 as stationary phase for chromatographic separation of pharmaceutical molecules

Fluorine-functionalized covalent organic frameworks (F-COFs), owing to their multiple interactions such as F-F forces and hydrophobicity, have been widely used as candidate materials for stationary phases and other analytical purposes. How to incorporate F-COFs with a silica matrix (SiO 2 ) through a low-energy consumption method, and investigating the chromatographic properties for pharmaceutical targets, is of vital importance and requires significant further research. In this study, pentafluorophenyl (PFP) was used as a functional group to prepare PFP-COF@SiO 2 at room temperature through two distinct synthetic approaches. The resulting PFP-COF@SiO 2 materials, designated as I and II, were systematically characterized, and their chromatographic performances, influential factors, and retention mechanisms were investigated. These two COF materials demonstrated similar material properties and effective separation towards phenolic acids, alkaloids and antiviral drugs. The results indicated that the designed two synthetic routes were to some extent tolerable and compatible with the order of reagent addition. This work offers a novel method for preparing PFP-COF@SiO 2 stationary phases oriented for pharmaceutical chromatographic applications.