Synthesis and Characterization of Liquid Crystal Type Stationary Phases on a Silica Hydride Surface

Abstract

Two liquid crystal materials, 4-methoxyphenyl-4-allyloxybenzoate and cholesteryl-10-undecenoate, containing terminal olefin groups are bonded to a silica hydride surface via a metal complex catalyzed hydrosilation reaction. Bonding is confirmed by DRIFT, carbon-13 CP-MAS NMR and DSC. The effects of different catalysts, reaction temperature, catalyst to olefin ratio, and reaction time were studied to maximize the surface coverage. Chromatographic studies indicate that these bonded materials behave similarly to liquid crystal phases prepared by organosilanization. The hydrosilation method offers the possibility of bonding a wider variety of liquid crystal moieties in order to utilize the unique separation properties of these materials.