CHROMATOGRAPHIC-SEPARATION OF GEOMETRICAL-ISOMERS USING HIGHLY ORIENTED POLYMER-IMMOBILIZED SILICA-GELS

Poly(octadecyl acrylate) having a reactive group at one side of the terminal group was synthesized and immobilized on porous silica gels. Differential scanning calorimetric measurement indicated that the immobilized polymer underwent a crystal-to-isotropic phase transition on silica gels. Using a packed column, a remarkably high separation factor for geometrical isomers of stilbene was observed in the crystal-state temperature range, although no similar separation was observed with octadecylated silica gels. It was estimated by calculation of the HOMO that this specific retention includes charge-transfer interactions from double bonds of solutes to acrylate moieties of the stationary phase.