Synthesis and evaluation of a ferrocene-bonded silica phase for reversed-phase high-performance liquid chromatography

Abstract

Key WardsColumn liquid chromatography Ferrocene-bonded silica stationary phase re-re Interactions Hydrophobic interactions SummaryThe preparation, characterization, and potential liquid chromatographic applications of a ferrocene-bonded silica stationary phase are presented. The phase was prepared by covalent bonding of ferrocene-derivatized aminosilane to silica gel then end-capping with trimethylchlorosilane. Use of the new stationary phase enabled good separations of alkylbenzenes, halobenzenes, polycyclic aromatic hydrocarbons, and even basic compounds under reversed-phase conditions. The linear relationship between log k (where k is the retention factor) and the number of rc electrons (n~) in the structures of polyaromatic hydrocarbons indicates that the mechanism of retention on the new stationary phase involves strong re-re interaction with one of the cyclopentadienyl (Cp) groups of the ferrocene. The retention increment for a methylene group was calculated. The value indicates that the mechanism of retention on the new stationary phase also involves a strong hydrophobic interaction, so the phase enables effective separation of compounds with a benzene ring.

Evaluation of the retention characteristics of ferrocene-bonded silica stationary phase and other silica-based reversed phases for HPLC using linear solvation energy relationships

“…This indicates that the rt-rt interaction between the solutes and the stationary phase is significant. This result is agreed with our previous study [11].…”

“…Fc-SiO2 was ferrocene-bonded phase based on Kromasil silica (,pore size= 100A) [11]. C1~-sio2 was Hypersil C1~ (Phenomenex; pore size = 120A ).…”

4-Chloro-6-pyrimidinylferrocene modified silica gel: A novel multiple-function stationary phase for mixed-mode chromatography

“…Since Delville [23][24] and Zuo [25][26] reported the application of ferrocene as the stationary phase, it has attracted extensive attention in liquid chromatography [27] due to its varieties of separation mechanisms, including hydrophobic, hydrogen bonding, π-π, dipole-dipole and charge-transfer interactions. Complexing properties of ferrocene receptors depend mainly on the type and arrangement of binding site.…”

Development of N-ferrocenyl(benzoyl)amino-acid esters stationary phase for high performance liquid chromatography

“…The grafting on silica gel of electron acceptor molecules bearing transition metal metallocenes [1][2][3][4][5] is another investigated field of research [6][7]. In recent years, the ferrocene-bonded stationary phase has attracted considerable attention in liquid chromatography due to its varieties of separation mechanisms, including hydrophobic, hydrogen bonding, π-π, dipole-dipole and charge-transfer interactions [8][9][10][11][12]. Complexing properties of ferrocene receptors depend mainly on the type and arrangement of binding site.…”

“…Delville group [8][9] and Zuo group [10][11] demonstrated that the stationary-phase, bonded with covalently linking ferrocene of so-called "organometallic/inorganic" hybrid materials, exhibited high selectivity towards the separation of alkylbenzenes, halobenzenes, PAHs and aniline derivatives under normal-phase (NP) or reversed-phase (RP) conditions.…”