| Crown ether is a macrocyclic polyether with many voids inside.Many polyethers are similar to crown in shape.Their lipophilic ones are located at the outer edge,and the electron-rich heteroatoms such as N,O and S are located inside.After the synthesis of crown ether by Sogah and Cram in the 1970s,people found many uses of crown ether,such as crown ether as chiral stationary phase.This paper synthesized six oxygen benyl crown ethers,five oxygen benyl crown ethers and brominated crown ethers,and investigated their properties as chiral stationary phases.(1)The possibility of synthesizing 6 oxygen benyl crown ethers as CSP was studied.21 amino acids were separated,and 20 amino acids had good resolution effect.The self-made chromatographic column could resolve some amino acids at room temperature and water as mobile phase.It was environmentally friendly,and the chromatographic column life was longer than commercial column.The resolution performance was almost unchanged after 5 months under strong acid conditions with p H=1.00.(2)The possibility of using 6 oxygen brominated crown ethers as CSP was also studied.21 amino acids were separated,and 20 amino acids were well recognized.The self-made chromatographic column can resolve some amino acids with water mobile phase at 25~oC and environmentally friendly,too.The resolution performance is unchanged after 5 months with p H=1.00 mobile phase.(3)Similarly,two kinds of 5-oxygen crown ether materials,phenyl crown ether-5and brominated crown ether-5,were synthesized.They were immobilized on spherical C18 silica gel by coating to obtain their chiral stationary phase.The CSP column was used to resolve some chiral substances.The experimental results showed that they possessed enantioselective characteristic. |
