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

Poly(octadecyl acrylate) having a reactive group at one side of the te rminal group was synthesized and immobilized on porous silica gels. Di fferential scanning calorimetric measurement indicated that the immobi lized polymer underwent a crystal-to-isotropic phase transition on sil ica gels. Using a packed column, a remarkably high separation factor f or geometrical isomers of stilbene was observed in the crystal-state t emperature range, although no similar separation was observed with oct adecylated silica gels. It was estimated by calculation of the HOMO th at this specific retention includes charge-transfer interactions from double bonds of solutes to acrylate moieties of the stationary phase.