Single-handed helical and C-shaped 3-aminophenol-formaldehyde resin nanotubes were prepared via a supramolecular templating approach. The chiral templates and 3-aminophenol were initially organized into helical nanori...Single-handed helical and C-shaped 3-aminophenol-formaldehyde resin nanotubes were prepared via a supramolecular templating approach. The chiral templates and 3-aminophenol were initially organized into helical nanoribbons, followed by the adsorption of formaldehyde onto the surfaces of the helical nanoribbons. Subsequent to polymerization and further thermosetting of the resin oligomers, 3-aminophenol-formaldehyde resin nanotubes were obtained after removing the templates. When low amounts of 3-aminophenol were added, straight C-shaped 3-aminophenol-formaldehyde resin nanotubes were obtained. Increasing the amount of added 3-aminophenol led to the formation of single-handed helical nanotubes instead. When the single-handed helical resin nanotubes were car- bonized at 900 ~C under Ar, single-handed helical carbonaceous nanotubes were obtained. Raman spectrum indicates that this carbon is predominantly amorphous. Circular dichroism spectra illustrate that both the helical resin nanotubes and the carbonaceous nanotubes exhibit optical activity. This work indicates that the added amount and the edge-adsorption mode of the precursors on the templates determine the final morphology and chirality of the products.展开更多
Chiral conjugated polymers with controlled mesoscopic helicity are gaining attention for enantioseparation and asymmetric catalysis.However,achieving on-demand chirality and processability remain challenging.Herein,we...Chiral conjugated polymers with controlled mesoscopic helicity are gaining attention for enantioseparation and asymmetric catalysis.However,achieving on-demand chirality and processability remain challenging.Herein,we exploit supramolecular coordination polymers formed by Mn^(2+)and chiral phenylglycine derivatives(L-/D-16PhgCOOH)as templates,using m-phenylenediamine as the monomer to synthesize chiral poly(m-phenylenediamine)(PMPD).In the Mn^(2+)-templated system,the PMPD’s handedness is opposite to the molecular chirality of L-/D-16PhgCOOH,while in the Mn^(2+)-free system,the PMPD handedness aligns with that of the template molecule.This method allows for helicity switching of chiral polymers within a single chirality template system.The introduction of Mn^(2+)is demonstrated to disrupt and reconstitute the supramolecular interactions in the co-assembly,influencing subsequent supramolecular stacking patterns.Carbonizing the resulting PMPDs directly produces chiroptical active nitrogen-doped carbonaceous nanomaterials that inherit the original helicity.Moreover,incorporating F-127 into the polymerization system enhances the aspect ratio of PMPDs,facilitating their delicate processing into chiral self-supporting two-dimensional films and three-dimensional foams.With abundant Lewis basic sites,these chiral polymers offer versatile platforms for novel chiral host-guest interactions.展开更多
基金Supported by the National Natural Science Foundation of China（Nos.51473106, 21574095） and the Science and Technology Plan（Nano Special） of Suzhou, China（No.ZXG201415）.
文摘Single-handed helical and C-shaped 3-aminophenol-formaldehyde resin nanotubes were prepared via a supramolecular templating approach. The chiral templates and 3-aminophenol were initially organized into helical nanoribbons, followed by the adsorption of formaldehyde onto the surfaces of the helical nanoribbons. Subsequent to polymerization and further thermosetting of the resin oligomers, 3-aminophenol-formaldehyde resin nanotubes were obtained after removing the templates. When low amounts of 3-aminophenol were added, straight C-shaped 3-aminophenol-formaldehyde resin nanotubes were obtained. Increasing the amount of added 3-aminophenol led to the formation of single-handed helical nanotubes instead. When the single-handed helical resin nanotubes were car- bonized at 900 ~C under Ar, single-handed helical carbonaceous nanotubes were obtained. Raman spectrum indicates that this carbon is predominantly amorphous. Circular dichroism spectra illustrate that both the helical resin nanotubes and the carbonaceous nanotubes exhibit optical activity. This work indicates that the added amount and the edge-adsorption mode of the precursors on the templates determine the final morphology and chirality of the products.
基金supported by the National Natural Science Foundation of China(U20A20257)the National Key Research and Development Program of China(2022YFB3805803).
文摘Chiral conjugated polymers with controlled mesoscopic helicity are gaining attention for enantioseparation and asymmetric catalysis.However,achieving on-demand chirality and processability remain challenging.Herein,we exploit supramolecular coordination polymers formed by Mn^(2+)and chiral phenylglycine derivatives(L-/D-16PhgCOOH)as templates,using m-phenylenediamine as the monomer to synthesize chiral poly(m-phenylenediamine)(PMPD).In the Mn^(2+)-templated system,the PMPD’s handedness is opposite to the molecular chirality of L-/D-16PhgCOOH,while in the Mn^(2+)-free system,the PMPD handedness aligns with that of the template molecule.This method allows for helicity switching of chiral polymers within a single chirality template system.The introduction of Mn^(2+)is demonstrated to disrupt and reconstitute the supramolecular interactions in the co-assembly,influencing subsequent supramolecular stacking patterns.Carbonizing the resulting PMPDs directly produces chiroptical active nitrogen-doped carbonaceous nanomaterials that inherit the original helicity.Moreover,incorporating F-127 into the polymerization system enhances the aspect ratio of PMPDs,facilitating their delicate processing into chiral self-supporting two-dimensional films and three-dimensional foams.With abundant Lewis basic sites,these chiral polymers offer versatile platforms for novel chiral host-guest interactions.
