Preparation And Chiral Recognition Of Helical Poly (Phenylacetylene)-Silicon Based Hybrid Chiral Stationary Phase

Poly(phenylacetylene)derivatives possessing helical conformation in main chains are used for the preparation of chiral stationary phases(CSPs)for high-performance liquid chromatography(HPLC)due to their good chiral recognition abilities.Until now,Most of Poly(phenylacetylene)chiral stationary phases are prepared by coating or immobilizing and the chiral polymers are below 20wt%.Increasing the loading of chiral polymers is beneficial to improve the separation ability of chiral stationary phases.The hybrid chiral stationary phases have attracted attention because they can support more chiral polymers and have good solvent resistance.In this thesis,The spiral poly(phenylacetylene)copolymer bearing a proline tripeptide derivative was synthesized,and the helical poly(phenylacetylene)-silicon based hybrid chiral stationary phase was prepared.The silica microsphere seeds were synthesized by Stober method,then the seeds were grown continuously by seed growth method,the porogen was added during the seed growth process.The porous silica microspheres with a particle size of about 5?m were prepared.The morphology and pore size of the silica microspheres were tested by SEM,XRD,BET,etc.The influence of reaction conditions on the spherical shape and particle size was discussed,and the preparation process of porous silica microspheres was optimized,which laid the foundation for the preparation of the helical poly(phenylacetylene)-silicon based hybrid chiral stationary phase.The phenylacetylene monomer bearing proline tripeptide derivative,N-(4-ethynylphenylcarbonyl)-L-prolyl prolyl proline methyl ester(PAA-L-t Pro-e),was synthesized via Sonagashira coupling reaction,elimination,and amidation reaction.A novel monomer,N-(4-ethynylphenylcarbonyl)-aminopropyltriethoxysilane(PA-APTES),was synthesized through amidation reaction and characterized by ¹H NMR.Copolymerization of PAA-L-t Pro-e and PA-APTES was carried out by using Rh(nbd)BPh₄ as a catalyst in CHCl₃to give a copolymer CP-PAA-L-t Pro-e.The structure of copolymer was characterized by¹H NMR,IR,Roman.The results showed that the main chain of the copolymer possessed cis-transoid configuration.The copolymer was invesgated vis polarimeter and circular dichroism(CD)spectra,results indicated the main chain of the copolymer has a helical conformation,and the solvent and temperature have a significant effect on the helical conformation of the copolymer main chain.The copolymer CP-PAA-L-t Pro-e was introduced in the process of preparing porous silica microspheres by seed growth method and the helical poly(phenylacetylene)-silicon based hybrid chiral stationary phase was prepared and characterized by SEM,BET,IR,TG,etc.The stationary phase has a uniform and regular spherical shape with a particle size of about 6?m and a content of helical polyphenylacetylene of 33wt%.The hybrid chiral stationary phase has good chiral recognition ability and solvent resistance,results indicated the separation factor?of rac-17(N¹,N²-diphenylcyclohexane-1,2-dicarboxamide)on the helical poly(phenylacetylene)-silicon based hybrid chiral stationary phase reached 3.43 using hexane/isopropanol/chloroform(v/v/v,94/1/5)as the eluent.