Controlled Synthesis And Property Of Polysaccharide Carbamates Bearing Bulky Terphenyl Groups

Polysaccharide carbamates are well-known to exhibit excellent chiral recognition ability.The properties,structure and position of substituent on phenyl have influence on chiral recognition ability of polysaccharide carbamates.The resolution power of those bearing para-substituents is much higher than that of ortho-or meta-substituted derivatives.Polysaccharide carbamates traditionally have small substituents,and the study on the introduction of bulky functional side chains has been much less reported.The influence of the bulky side chains on the structure and performance is not published yet.As a typical liquid crystal functional side chains,the terphenyl structure because of its bulky and strong rigid properties has become one of the hot functional groups in recent years.In order to research the influence of chiral recognition ability polysaccharide carbamates bearing bulky liquid crystal side chains did and develop polysaccharide carbamates having functions,the research on the synthesis and property of cellulose and amylose carbamates bearing bulky terphenyl groups was performed in this study.The novel polysaccharide carbamates bearing para-substituted bulky terphenyl groups were synthesized by Suzuki reaction,Sandmeyer reaction,Grignard exchange reaction and esterification reaction.The structures of the mediums and final derivatives were then characterized by fourier transform infrared(FT-IR),nuclear magnetic resonance 1H NMR and 13C NMR,respectively.The coated-type CSPs based on the obtained polysaccharide carbamates were prepared by the traditional coating method,and the chiral columns for HPLC were prepared by slurry method.The chiral recognition abilities of polysaccharide carbamates were evaluated through enantioseparation of some chiral compounds on the novel CSPs by HPLC.The structure of the polysaccharide carbamates were discussed by circular dichroism.The liquid crystallinity of the obtained novel polysaccharide carbamates was evaluated by differential scanning calorimetry and polarizing microscope.The effects of the liquid crystallinity and chiral recognition ability of the bulky terphenyl groups on the structure of the polysaccharide derivatives were discussed.It indicated that novel polysaccharide carbamates bearing bulky terphenyl groups exhibited good chiral recognition ability,the novel polysaccharide carbamates can form lyotropic liquid crystal,suggesting that the derivatives possess good regularity.The amylose derivatives before and after processing have a large difference in chromatographic performance and liquid crystallinity.It may be mainly because the main chain of amylose derivative is more flexible and susceptible to the influence of bulky terphenyl groups.It is suggested that the main chain structure has the greatest impact on structure and properties of the polymers.There were no differences in the chromatographic and liquid crystallinity of the cellulose derivatives before and after processing.It indicated that the liquid crystallinity of the derivatives mainly depends on the high regularity of the main chain.And the orderly structure of the bulky terphenyl groups have little much effect on structure and properties of the derivatives.