Title
Helical poly(phenyl isocyanide)s grafted selectively on C-6 of cellulose for improved chiral recognition ability
Author
Hao Qian, Xiaofei Shen, Hailong Huang, Yan Zhang, Mingtao Zhang, Huiqing Wang, Zhongkai Wang
Year
2020
Journal
Carbohydrate Polymers
Abstract
Cellulose graft copolymers are an effective way to endow new properties to cellulose substrate, as well the rigidity, regularity, and helicity of the cellulose backbone could induce the self-assembly of supramolecular structures. In this work, right-handed helical poly(phenyl isocyanide)s (PPIn) were grafted selectively onto C-6-cellulose. Alkyne-terminated PPIn was synthesized by living polymerization of right-handed phenyl isocyanide monomer using an alkyne-terminated palladium(II) complex as an initiator/catalyst, and were grafted onto the C-6 of the cellulose backbone (Cell-6-g-PPIn) at various chain lengths using copper-catalyzed alkyne-azide cycloaddition (CuAAC) “click” chemistry. We confirmed the successful grafting by liquid 1H NMR and 13C NMR, as well as solid 13C NMR, FTIR, and GPC. After grafting onto cellulose, the right-handed chirality of PPIn was significantly increased by 111.2%. Additionally, the Cell-6-g-PPIn exhibited better chiral recognition of L-Phe-DNSP than PPIn alone. Therefore, the helical cellulose backbone has enhanced effect on preferred helix of PPIn.
Instrument
J-1500
Keywords
Circular dichroism, Stereochemistry, Chemical stability, Polymers