Silica-bonded Calixarenes in Chromatography: Enantioseparations on Molecular Basket Phases for Rapid Chiral LC

Abstract

The synthesis of a new type of chiral stationary phase, prepared from triethoxysilyl derivatives of calixarenes, and by the chemical immobilisation of these chiral molecular baskets to 3μm silica particles, is reported. Specifically, a silica-bonded calix[4]arene, funcrionalised at the lower rim with L-(-)-ephedrine, is prepared and packed into a short LC column for rapid chiral separations. Using reversed phase conditions and high flow rate, such new phases based on funcrionalised calixarenes are applicable to chiral aromatic and non-aromatic solutes and are capable of resolving the enantiomers of R(-) and S(+)-1-phenyl-2,2,2-trifluoroethanol in less than 45 seconds.

Key Words:

• Calixarene
• silica
• chiral
• stationary phases