Synthesis and Chiral Recognition Ability of a Poly(phenylenevinylene)-Encapsulated Amylose Derivative

Abstract

Abstract Poly(p-phenylenevinylene) (PPV) was found to be encapsulated in amylose during the polymerization of the precursor monomer in an aqueous solution. The resulting amylose–PPV composite can be further chemically modified by introducing various substituents into the hydroxy groups of the amylose using isocyanates and acetic anhydride. Here we report on the chemical modification of the amylose–PPV composite with 3,5-dimethylphenyl isocyanate in order to obtain a novel chiral packing material for resolving enantiomers by high-performance liquid chromatography (HPLC). The obtained 3,5-dimethylphenylcarbamated amylose–PPV was soluble in pyridine and exhibited a lyotropic liquid crystalline phase in a concentrated pyridine solution. The chiral recognition ability of the 3,5-dimethylphenylcarbamated amylose–PPV was different from that of amylose tris(3,5-dimethylphenylcarbamate) having no PPV rods in the helical cavity of the amylose and can resolve many racemic compounds into enantiomers. Among racemic compounds, cyclic dibenzamide and dibenzanilide derivatives were resolved on the 3,5-dimethylphenylcarbamated amylose–PPV better than amylose tris(3,5-dimethylphenylcarbamate). The difference in the enantioseparation abilities of these amylose-based chiral stationary phases for HPLC is discussed based on the difference in their helical structures.