A series of fluorinated racemic materials differing in the position of the fluorine atom on the aromatic nucleus of the molecule was synthesized. All proposed materials showed orthogonal SmA, synclinic SmC and anticlinical SmCA phase in an adequately wide temperature range. The mesomorphic properties of the new racemic materials were in good agreement with the properties of the pure (S) and (R) enantiomers.
The possibilities of enantioseparation of newly synthesized materials by chiral HPLC were tested on two chiral stationary phases based on amylose and cellulose. A surprising effect of the stationary phase of tris(3,5-dimethylphenylcarbamate) amylose on the elution order of the (R) and (S) enantiomers was observed in the separation, the elution order depending on the presence and position of fluorine as a substituent on the molecular nucleus (see figure). This phenomenon was first discovered and described for this type of material.
