Grafting Polymerization Of Graphene Oxide By Single-handed Helical Poly(phenyl Isocyanide)s And Their Application In Enantioselective Separation And Research On Pybox Ligands

Graphene-based polymer materials are attracting increasing attention because of their excellent and intriguing physical properties. In this paper,we report on a "grafting from" strategy to graft optical active helical poly(phenyl isocyanide)s polymer and copolymer onto graphene oxide (GO) nanosheets. First, alkyne-Pd(II) initiator was covalently bound onto GO nanosheets. Then living/control polymerization of chiral isocyanide monomer Mi and achiral one M2 sequentially took place to yield the designed GO/polymer composites Pl@GO and Pl-b-P2@GO featured single-handed helical poly(phenyl isocyanide) chains growing from the GO nanosheets. Post modification was also carried out to prepare P1-b-P3@GO through hydrolysis of P2 to improve the hydrophilic ability, which was tested by the dispersibility and contact angle test. The successful covalent bonding of poly(phenyl isocyanide)s chains onto GO nanosheets was certified by several cross evidences including scan emission microscopy,atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The optical activity of three GO/polymer composites were determined by circular dichrosim (CD) and UV-vis spectra, exhibiting that the chiral information has been introduced through the grafted single-handed helical polymer chains successfully. In addition, the resulting GO/polymer composites were explored as a chiral additive to induce enantioselective crystallization of racemic organic molecules.Rod-like L-alanine crystals were preferentially induced to form by composites bearing right-handed helical poly(phenyl isocyanide)s. The highest enantiomeric excess value of the induced crystals could up to 76%, displaying the potential applications in the future.In addition, a small part of this paper focuses on the research of metal complexes,two different Pybox ligands were synthesized,one stable cobalt metal complexes with the field induced slow magnetic relaxation behaviour was researched.