Advantages of polar organic solvent chromatography for enantioseparation of chiral liquid crystals.

Three sets of fluorinated chiral liquid crystals were used to explore the polar organic solvent chromatography mode for their enantioseparation. The materials include a set of newly synthesized compounds with chiral center derived from 2-hexanol and two sets of compounds with chiral center derived from 2-/3-octanol. Baseline enantioseparation of all materials was achieved using binary mobile phases without additives.

Enantioseparation of liquid crystals and their utilization as enantiodiscrimination materials.

Liquid crystals can partake in enantioseparations in several different ways. Enantiomeric purity of chiral liquid crystals as analytes is often determined using enantioselective liquid or supercritical fluid chromatography. At the same time, chiral liquid crystalline materials can be applied as a chiral selector or they can function as an auxiliary material for a different chiral selector enabling enantioseparation of various solutes in miscellaneous separation techniques.

Enantioselective high-performance liquid chromatography of aryl-substituted oxazolines as an efficient tool for determination of chiral purity of serine medicinal components.

A new approach for the evaluation of chiral purity of serine esterification products bearing long-chain alkyl substituents was developed. The compounds were simply converted to aryl-substituted oxazolines which: (i) facilitates effective chromatographic enantioseparation and (ii) enables direct detection using ultraviolet absorption. The method employs a polysaccharide-based chiral stationary phase and allows enantioseparation of highly stable oxazoline products in less than 6 min using a simple binary mobile phase.

How mobile phase composition and column temperature affect enantiomer elution order of liquid crystals on amylose tris(3-chloro-5-methylphenylcarbamate) as chiral selector.

A comprehensive study into the effects of mobile phase composition and column temperature on enantiomer elution order was conducted with a set of chiral rod-like liquid crystalline materials. The analytes were structurally similar and comprised variances such as length of terminal alkyl chain, presence of chlorine, number of phenyl rings, and type of chiral center. Experiments were carried out in polar organic and reversed-phase modes using amylose tris(3-chloro-5-methylphenylcarbamate) immobilized on silica gel as the chiral stationary phase.

Enantiorecognition ability of different chiral selectors for separation of liquid crystals in supercritical fluid chromatography; critical evaluation.

Comprehensive study of enantioselective potential of eight different chiral stationary phases for chiral liquid crystal-forming molecules was conducted. The tested columns were: (i) polysaccharide-based Trefoil AMY1, CEL1 and CEL2 and (ii) superficially porous particles packed TeicoShell, VancoShell, TagShell, DMP-MaltoShell, and NicoShell. To test their enantioselective potential for these separations, twenty racemic mixtures of rod-like liquid crystalline materials comprising three different types of chiral centres and various other structural differences were used.

Ultra-performance supercritical fluid chromatography: A powerful tool for the enantioseparation of thermotropic fluorinated liquid crystals.

A fast and simple supercritical fluid chromatography method for the enantioseparation of twenty newly synthesized orthoconic antiferroelectric liquid crystals is reported for the first time. The effects of alkoxy spacer length and fluorine atom presence and position in the phenyl ring on chromatographic behavior were investigated. Baseline enantioseparation of all compounds was achieved using simple mobile phases consisting of carbon dioxide and alcohol as cosolvent on (3,5-dimethylphenylcarbamate) derivative of amylose as chiral stationary phase.