Conjugated block copolymers have gained increasing interests in recent years. Development of a novel method for facile synthesis of conjugated block copolymers with desired structures and functions is greatly desired....Conjugated block copolymers have gained increasing interests in recent years. Development of a novel method for facile synthesis of conjugated block copolymers with desired structures and functions is greatly desired. In this mini review, we summarized the recent advances in one-pot synthesis of conjugated block copolymers containing π-conjugated polythiophene and helical polyisocyanide segments by using a nickel（Ⅱ） complex as single catalyst. The sequential living polymerization of the two monomers proceeded in a controlled manner, affording expected block copolymers in high yields with controlled molecular weights（Mns） and narrow molecular weight distributions（Mw/Mns）. By using this method, a family of block copolymers with expected structure and tunable compositions can be facilely prepared. Introducing functional groups onto the pendant, these block copolymers can exhibit interesting self-assembly property, tunable light emission and multi-responsiveness.展开更多
Helical poly(phenylacetylene)s(PPAs)have received extensive attention because of their features in dynamic chirality and promising applications.Therefore,understanding relationship among the polymer molecular structur...Helical poly(phenylacetylene)s(PPAs)have received extensive attention because of their features in dynamic chirality and promising applications.Therefore,understanding relationship among the polymer molecular structures,polymerization conditions and tunability of their chirality is of key scientific value.Recently,we developed a novel class of dendronized PPAs carrying 3-fold dendritic oligo(ethylene glycols)(OEGs)via alanine linkage,and found that these bulky polymers exhibited tunable helical conformations through thermally-mediated dehydration and aggregation.Herein,we report on synthesis of a homologous series of dendronized PPAs that carry 2-fold,3-fold or 6-fold dendritic OEG pendants,and focus on effects of molecular topological structures,peripheral units and polymerization solvents on the thermoresponsiveness and their conformation switching behaviors.Effects of branching density and peripheral units(ethoxyl or methoxyl)of the dendritic OEG pendants were examined,and found to play a decisive role on the helical conformation and thermoresponsiveness of these dendronized PPAs due to their different bulkiness and overall hydrophilicity.In addition,different polymerization solvents were checked for their possible influence on the polymerization,thermoresponsive behavior and the chirality of the resulting polymers.For polymerization in selective solvents like water or methanol,the obtained dendronized PPAs exhibited weak thermal transitions,while polymerization in non-selective solvent like THF furnished PPAs with characteristic thermoresponsive behavior,indicating that solvents were involved in the process of polymerization of the dendronized macromonomers.More interestingly,different chiralities of the PPAs through polymerization in various solvents were retained,irrelevant to the purification process and solvents treatments.This work suggests that the topological structures together with polymerization solvents can modulate the thermoresponsive behavior and helical conformation of the dendronized PPAs.展开更多
Three novel enantiopure phenyl isocyanide monomers with BH3-protected phosphine functional group were designed and synthesized. Polymerization of these monomers using a alkyne-Pd（II） complex as a catalyst led to the...Three novel enantiopure phenyl isocyanide monomers with BH3-protected phosphine functional group were designed and synthesized. Polymerization of these monomers using a alkyne-Pd（II） complex as a catalyst led to the formation of respective helical polyisocyanides in high yields with controlled molecular weights（Mns） and narrow molecular weight distributions（Mw/Mns）. Removing the protecting BH3 groups afforded helical poly（phenyl isocyanide）s bearing phosphine pendants. Thanks to the chiral induction of monomer, the isolated helical polyisocyanides showed high optical activity, as revealed by circular dichroism（CD） and absorption spectroscopies and polarimetry. The helical structures of these polymers were quite stable in various organic solvents with different polarities and in a wide temperature range. Moreover, these helical polymers could be used as organocatalysts and showed good performance in enantioselective cross Rauhut-Currier reaction. The enantiomeric excess（ee） values of the isolated products of cross Rauhut-Currier reaction could be up to 90%. The polymer organocatalysts could be easily recovered from the reaction mixtures and reused at least five times in the reaction without significant loss of their enantioselectivities and catalytic activities.展开更多
A coordination polymer [Co(dpa)prz0.5]n(1) with double-helix chains has been constructed hydrothermally using H2dpa(H2dpa=diphenic acid),prz(prz=piperazine) and Co(NO3)2.6H2O.The structure and magnetic properties of t...A coordination polymer [Co(dpa)prz0.5]n(1) with double-helix chains has been constructed hydrothermally using H2dpa(H2dpa=diphenic acid),prz(prz=piperazine) and Co(NO3)2.6H2O.The structure and magnetic properties of the complex were investigated.The complex crystallizes in triclinic system and P1 space group.Each Co atom is five-coordinated and takes a distorted tetragonal pyramid geometry.Two carboxylates of the H2dpa ligands bridge four Co(Ⅱ) ions to form infinite right-handed or left-handed helical-C-O-Co-chains.The two types of helical chains are interconnected to each other through the Co (Ⅱ) centers to produce double-helix chains.The chains form a 2D sheet through the coordination interaction of prz molecules between adjacent chains.The sheets are further interlinked by hydrogen bond interactions to generate 3D coordination frameworks.Magnetic studies for complex 1 show stronger antiferromagnetic coupling between the Co(Ⅱ) ions.展开更多
A new 3D complex,[Co（L）（bpe）0.5（H2O）2]n（1,H2 L = 5-iodo-benzene-1,3-dioxyacetic acid,bpe = 1,2-bis（4-pyridyl）ethylene）,has been hydrothermally synthesized and structurally characterized by elemental analysis...A new 3D complex,[Co（L）（bpe）0.5（H2O）2]n（1,H2 L = 5-iodo-benzene-1,3-dioxyacetic acid,bpe = 1,2-bis（4-pyridyl）ethylene）,has been hydrothermally synthesized and structurally characterized by elemental analysis,IR and X-ray diffraction.It is formulated as C16H16 Co INO8,crystallizes in monoclinic,space group P21/c,with a = 9.806（2）,b = 6.5492（13）,c = 28.187（8） A,β = 100.12（3）°,V = 1782.0（7） A^3,Z = 4,Dc = 1.998 g/m^3,F（000） = 1052,Μr = 536.13,the final R = 0.0393 and w R = 0.0858 for 3134 observed reflections with I 〉 2σ（I）.Complex 1 displays a 3D framework with multiform helical features,left-and right-handed triple helical braids and single helical chains,which can be simplified as a new type of（3,4）-connected lattice with a（6·10^2）（6^2·10^4） SchlAfli symbol.Moreover,the thermal analysis of complex 1 has also been investigated.展开更多
The ＂sergeants and soldiers rule＂ occurring in helical copolymer emulsions derived from an achiral monomer （M1） and a chiral monomer （M2） was observed. TEM, GPC, and 1H-NMR techniques in combination demonstrate ...The ＂sergeants and soldiers rule＂ occurring in helical copolymer emulsions derived from an achiral monomer （M1） and a chiral monomer （M2） was observed. TEM, GPC, and 1H-NMR techniques in combination demonstrate the formation of nanoparticles constituted by the copolymers. CD and UV-Vis spectra show the （co）polymer chains in the nanoparticles adopt helical structures of a predominant helicity, and the copolymers follow the ＂sergeants and soldiers rule＂ in forming helical structure.展开更多
A novel manganese（Ⅱ） coordination polymer with 2-（4-carboxyphenoxy） benzoic acid （2,4＇-H2oba） and 1,10-phenanthroline （1,10-phen） has been prepared by hydrothermal synthesis and characterized by single-cryst...A novel manganese（Ⅱ） coordination polymer with 2-（4-carboxyphenoxy） benzoic acid （2,4＇-H2oba） and 1,10-phenanthroline （1,10-phen） has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and elemental analysis. Compound [Mn（2,4＇-oba）（1,10-phen）] is of monoclinic system, space group P21/n with a = 7.960（1）, b = 15.464（2）, c = 18.703（3）A, β = 99.976（2）°, V = 2267.5（6） A^3, Z = 4, Mr = 491.35, Dc = 1.439 g/cm^3, F（000） = 1004 and μ = 0.623 cm·1. The final R = 0.0419 and wR = 0.0978 for 3444 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the oba2-ligands adopt a bis（chelating bidentate） mode to link two Mn（Ⅱ） centers to form an infinite 1D helical chain. Furthermore, a 3D supramolecular structure was formed by π-π stacking interactions and hydrogen bonds.展开更多
Two novel coordination polymers with helical chains, {[Zn（L）（H2O）]·H2O}n（1） and {[Zn（L）（p-bix）]·3.5H2O}n（2）, where H2 L = 5-（4-hydroxypyridinium-1-ylmethyl） isophthalic acid and p-bix = 1,4-bis...Two novel coordination polymers with helical chains, {[Zn（L）（H2O）]·H2O}n（1） and {[Zn（L）（p-bix）]·3.5H2O}n（2）, where H2 L = 5-（4-hydroxypyridinium-1-ylmethyl） isophthalic acid and p-bix = 1,4-bis（imidazol-1-ylmethyl）benzene, have been hydrothermally synthesized, and charac-terized by elemental analysis, powder X-ray diffraction（PXRD）, IR, thermal gravimetric analyses（TGA） and also by single-crystal X-ray diffraction. Both complexes 1 and 2 crystallize inmonoclinic, space group P21/c. Compound 1 displays a two-dimensional（2D） structure with two distinct types of helical chains; 2 shows a layered coordination polymer with two types of helical chains and features an interesting 2D→3D interdigitated architecture. Meanwhile, the luminescent properties of 1 and 2 have also been investigated in detail.展开更多
A new allylnickel(II) complex([S(R)]-N-[(1 S)-2-(diphenylphosphino)-1-phenylethyl]-2-methyl-2-propanesulfinamide)(2,2,2-trifluoroacetato-k O)(p-allyl)nickel(2) was designed and prepared by using chiral phosphine. 2 wa...A new allylnickel(II) complex([S(R)]-N-[(1 S)-2-(diphenylphosphino)-1-phenylethyl]-2-methyl-2-propanesulfinamide)(2,2,2-trifluoroacetato-k O)(p-allyl)nickel(2) was designed and prepared by using chiral phosphine. 2 was revealed to efficiently initiate the polymerization of L-and D-N-(1-(dodecylamino)-1-oxopropan-2-yl)-4-(propa-1,2-dien-1-yloxy)-benzamide(L-1 and D-1) in a living/controlled chain growth manner. Polymerization kinetics of L-1 and D-1 indicated that L-1 preferentially polymerized over the antipode D-1 by a factor of 1.9. In block copolymerization of rac-1 using the poly-L-150 as the macroinitiator, the polymerization proceeded in enantiomer-selective manner. It was found that enantiomeric excess(ee) value of the recovered monomer increased with the monomer conversion and finally reached to the maximum of 34%. These results suggest this chiral phosphine complex exhibits enantiomer-selectivity for the polymerization of chiral allene derivative monomer.展开更多
Single-ion conducting polymer electrolytes have attracted great attention as safe alternatives to liquid electrolytes in high energy density lithium-ion batteries.Herein,we report the first example of a crystalline an...Single-ion conducting polymer electrolytes have attracted great attention as safe alternatives to liquid electrolytes in high energy density lithium-ion batteries.Herein,we report the first example of a crystalline anionic helical polymer as a single lithium-ion conducting solid polymer electrolyte(SPE).Single-crystal X-ray analysis shows that the polymer folds into densely packed double helices,with bundles of unidirectional negatively charged channels formed that can facilitate lithium-ion transportation.展开更多
Circularly polarized luminescence(CPL)-active nanomaterials have attracted tremendous attention.However,it is still a big challenge to conveniently fabricate multi-color and white CPL-active nanomaterials on a large s...Circularly polarized luminescence(CPL)-active nanomaterials have attracted tremendous attention.However,it is still a big challenge to conveniently fabricate multi-color and white CPL-active nanomaterials on a large scale.Herein,a simple and scalable approach to achieve the above goals is presented.Multicolor CPL-active nanofibers are fabricated from chiral helical substituted polyacetylene,achiral fluorescent dyes and polyacrylonitrile via uniaxial electrospinning;the highest luminescence dissymmetry factor(glum)of the resulting nanofibers can reach 10^(−2).Furthermore,white CPL-active nanofibers are obtained by coaxial electrospinning,in which the resulting core-shell structure has excellent adjustability and can be utilized to physically isolate different fluorescent dyes to reduce energy transfer efficiency;therefore,stable white CPL emissions can be achieved with high g_(lum) values up to 10^(−3).Notably,the prepared white-emission CPL nanofibrous films show bright white circularly polarized light when coated on UV chips,demonstrating their future application in constructing low-cost and flexible light-emitting devices such as circularly polarized light-emitting diodes.展开更多
To understand the relationships between channel size and ion selectivity,we have developed a new type of artificial ion channel based on pore-forming helical polymers consisting of phenanthrolineoxadiazole units with ...To understand the relationships between channel size and ion selectivity,we have developed a new type of artificial ion channel based on pore-forming helical polymers consisting of phenanthrolineoxadiazole units with a pore aperture 2.3A close to the diameter of the Na^(+)ion(2.04A).Successful preparation of high molecular weight helical polymers(HP1)gives rise to a 4.6 nm long artificial unimolecular transmembrane channel.The transport property of artificial channel HP1 was elaborately investigated by means of vesicle-based kinetic assay and symmetry/asymmetry bilayer membrane(BLM)experiments as well.These results unambiguously demonstrate that HP1 is a Na^(+)-selective channel with extremely high transport activity(EC_(50)=0.017 mol% relative to lipid).Moreover,the Na^(+)/K^(+)selectivity ratio of HP1 reaches 1.9,as determined by asymmetry BLM experiments.Owing to the narrowest 2.3A size constraint so far,HP1 transport naked Na^(+)ion across the membrane,which represents a different Na^(+)transport mode from that of natural Na^(+)channels,which transports partially hydrated Na^(+)ions during transmembrane conduction.This study provides crucial insights on the chemical basis of ion selectivity in the field of ion channels.展开更多
A new zinc polymer, {Zn（O2CC12H8CO2）（H2O）}, or {Zn（DPHA）（H2O）}n （O2CC12H8CO2, DPHA = 1,1′ -biphenyl-2,2′-dicarboxylate dianion） has been synthesized under hydrothermal conditions. The crystal is of monocli...A new zinc polymer, {Zn（O2CC12H8CO2）（H2O）}, or {Zn（DPHA）（H2O）}n （O2CC12H8CO2, DPHA = 1,1′ -biphenyl-2,2′-dicarboxylate dianion） has been synthesized under hydrothermal conditions. The crystal is of monoclinic, space group P21/c with a = 12.8418（5）, b = 5.9505（2）, c = 17.2989（5） A, β = 104.020（2）°, V = 1282.52（8） A^3, C14H10O5Zn, Mr= 323.61, Z = 4, Dc = 1.676 g/cm^3,μ = 1.930 mm^-1, F（000） = 656, R = 0.0766 and wR = 0.1871 for 1775 observed reflections （I 〉 2σ（I））. It consists of Zn2（DPHA）2（H2O）2 units, which are further extended into a one-dimensional double helical-chain polymer via Zn-O bonding. The hydrogen bonding interactions extend the helical chains into a two-dimensional layer structure.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21622402,51673057 and 21574036)1000 plan Program for Young Talents of China
文摘Conjugated block copolymers have gained increasing interests in recent years. Development of a novel method for facile synthesis of conjugated block copolymers with desired structures and functions is greatly desired. In this mini review, we summarized the recent advances in one-pot synthesis of conjugated block copolymers containing π-conjugated polythiophene and helical polyisocyanide segments by using a nickel（Ⅱ） complex as single catalyst. The sequential living polymerization of the two monomers proceeded in a controlled manner, affording expected block copolymers in high yields with controlled molecular weights（Mns） and narrow molecular weight distributions（Mw/Mns）. By using this method, a family of block copolymers with expected structure and tunable compositions can be facilely prepared. Introducing functional groups onto the pendant, these block copolymers can exhibit interesting self-assembly property, tunable light emission and multi-responsiveness.
基金supported by the National Natural Science Foundation of China(Nos.21971160 and 21971161)Program for Professor of Special Appointment(No.Eastern Scholar TP2019039)at Shanghai Institutions of Higher Learning.
文摘Helical poly(phenylacetylene)s(PPAs)have received extensive attention because of their features in dynamic chirality and promising applications.Therefore,understanding relationship among the polymer molecular structures,polymerization conditions and tunability of their chirality is of key scientific value.Recently,we developed a novel class of dendronized PPAs carrying 3-fold dendritic oligo(ethylene glycols)(OEGs)via alanine linkage,and found that these bulky polymers exhibited tunable helical conformations through thermally-mediated dehydration and aggregation.Herein,we report on synthesis of a homologous series of dendronized PPAs that carry 2-fold,3-fold or 6-fold dendritic OEG pendants,and focus on effects of molecular topological structures,peripheral units and polymerization solvents on the thermoresponsiveness and their conformation switching behaviors.Effects of branching density and peripheral units(ethoxyl or methoxyl)of the dendritic OEG pendants were examined,and found to play a decisive role on the helical conformation and thermoresponsiveness of these dendronized PPAs due to their different bulkiness and overall hydrophilicity.In addition,different polymerization solvents were checked for their possible influence on the polymerization,thermoresponsive behavior and the chirality of the resulting polymers.For polymerization in selective solvents like water or methanol,the obtained dendronized PPAs exhibited weak thermal transitions,while polymerization in non-selective solvent like THF furnished PPAs with characteristic thermoresponsive behavior,indicating that solvents were involved in the process of polymerization of the dendronized macromonomers.More interestingly,different chiralities of the PPAs through polymerization in various solvents were retained,irrelevant to the purification process and solvents treatments.This work suggests that the topological structures together with polymerization solvents can modulate the thermoresponsive behavior and helical conformation of the dendronized PPAs.
基金financially supported by the National Natural Science Foundation of China (Nos. 21622402, 51673057 and 21574036)the 1000 plan Program for Young Talents of China
文摘Three novel enantiopure phenyl isocyanide monomers with BH3-protected phosphine functional group were designed and synthesized. Polymerization of these monomers using a alkyne-Pd（II） complex as a catalyst led to the formation of respective helical polyisocyanides in high yields with controlled molecular weights（Mns） and narrow molecular weight distributions（Mw/Mns）. Removing the protecting BH3 groups afforded helical poly（phenyl isocyanide）s bearing phosphine pendants. Thanks to the chiral induction of monomer, the isolated helical polyisocyanides showed high optical activity, as revealed by circular dichroism（CD） and absorption spectroscopies and polarimetry. The helical structures of these polymers were quite stable in various organic solvents with different polarities and in a wide temperature range. Moreover, these helical polymers could be used as organocatalysts and showed good performance in enantioselective cross Rauhut-Currier reaction. The enantiomeric excess（ee） values of the isolated products of cross Rauhut-Currier reaction could be up to 90%. The polymer organocatalysts could be easily recovered from the reaction mixtures and reused at least five times in the reaction without significant loss of their enantioselectivities and catalytic activities.
文摘A coordination polymer [Co(dpa)prz0.5]n(1) with double-helix chains has been constructed hydrothermally using H2dpa(H2dpa=diphenic acid),prz(prz=piperazine) and Co(NO3)2.6H2O.The structure and magnetic properties of the complex were investigated.The complex crystallizes in triclinic system and P1 space group.Each Co atom is five-coordinated and takes a distorted tetragonal pyramid geometry.Two carboxylates of the H2dpa ligands bridge four Co(Ⅱ) ions to form infinite right-handed or left-handed helical-C-O-Co-chains.The two types of helical chains are interconnected to each other through the Co (Ⅱ) centers to produce double-helix chains.The chains form a 2D sheet through the coordination interaction of prz molecules between adjacent chains.The sheets are further interlinked by hydrogen bond interactions to generate 3D coordination frameworks.Magnetic studies for complex 1 show stronger antiferromagnetic coupling between the Co(Ⅱ) ions.
基金the financial support by the Science and Technology Research Key Project Department of Education in Henan Province(14A150026)Nanyang Normal University Scientific Research Foundation Project(ZX2014041)
文摘A new 3D complex,[Co（L）（bpe）0.5（H2O）2]n（1,H2 L = 5-iodo-benzene-1,3-dioxyacetic acid,bpe = 1,2-bis（4-pyridyl）ethylene）,has been hydrothermally synthesized and structurally characterized by elemental analysis,IR and X-ray diffraction.It is formulated as C16H16 Co INO8,crystallizes in monoclinic,space group P21/c,with a = 9.806（2）,b = 6.5492（13）,c = 28.187（8） A,β = 100.12（3）°,V = 1782.0（7） A^3,Z = 4,Dc = 1.998 g/m^3,F（000） = 1052,Μr = 536.13,the final R = 0.0393 and w R = 0.0858 for 3134 observed reflections with I 〉 2σ（I）.Complex 1 displays a 3D framework with multiform helical features,left-and right-handed triple helical braids and single helical chains,which can be simplified as a new type of（3,4）-connected lattice with a（6·10^2）（6^2·10^4） SchlAfli symbol.Moreover,the thermal analysis of complex 1 has also been investigated.
基金supported by the National Natural Science Foundation of China (Nos. 21174010, 20974007)the Fundamental Research Funds for the Central Universities (ZZ1117)
文摘The ＂sergeants and soldiers rule＂ occurring in helical copolymer emulsions derived from an achiral monomer （M1） and a chiral monomer （M2） was observed. TEM, GPC, and 1H-NMR techniques in combination demonstrate the formation of nanoparticles constituted by the copolymers. CD and UV-Vis spectra show the （co）polymer chains in the nanoparticles adopt helical structures of a predominant helicity, and the copolymers follow the ＂sergeants and soldiers rule＂ in forming helical structure.
文摘A novel manganese（Ⅱ） coordination polymer with 2-（4-carboxyphenoxy） benzoic acid （2,4＇-H2oba） and 1,10-phenanthroline （1,10-phen） has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and elemental analysis. Compound [Mn（2,4＇-oba）（1,10-phen）] is of monoclinic system, space group P21/n with a = 7.960（1）, b = 15.464（2）, c = 18.703（3）A, β = 99.976（2）°, V = 2267.5（6） A^3, Z = 4, Mr = 491.35, Dc = 1.439 g/cm^3, F（000） = 1004 and μ = 0.623 cm·1. The final R = 0.0419 and wR = 0.0978 for 3444 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the oba2-ligands adopt a bis（chelating bidentate） mode to link two Mn（Ⅱ） centers to form an infinite 1D helical chain. Furthermore, a 3D supramolecular structure was formed by π-π stacking interactions and hydrogen bonds.
基金supported by Education Chamber of Henan Province(No.15A150068)
文摘Two novel coordination polymers with helical chains, {[Zn（L）（H2O）]·H2O}n（1） and {[Zn（L）（p-bix）]·3.5H2O}n（2）, where H2 L = 5-（4-hydroxypyridinium-1-ylmethyl） isophthalic acid and p-bix = 1,4-bis（imidazol-1-ylmethyl）benzene, have been hydrothermally synthesized, and charac-terized by elemental analysis, powder X-ray diffraction（PXRD）, IR, thermal gravimetric analyses（TGA） and also by single-crystal X-ray diffraction. Both complexes 1 and 2 crystallize inmonoclinic, space group P21/c. Compound 1 displays a two-dimensional（2D） structure with two distinct types of helical chains; 2 shows a layered coordination polymer with two types of helical chains and features an interesting 2D→3D interdigitated architecture. Meanwhile, the luminescent properties of 1 and 2 have also been investigated in detail.
基金sponsored by the National Natural Science Foundation of China(Nos.21622402,51673057,and 21574036)the Thousand Young Talents Program of China and the Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.sklssm201624)for Financial Support
文摘A new allylnickel(II) complex([S(R)]-N-[(1 S)-2-(diphenylphosphino)-1-phenylethyl]-2-methyl-2-propanesulfinamide)(2,2,2-trifluoroacetato-k O)(p-allyl)nickel(2) was designed and prepared by using chiral phosphine. 2 was revealed to efficiently initiate the polymerization of L-and D-N-(1-(dodecylamino)-1-oxopropan-2-yl)-4-(propa-1,2-dien-1-yloxy)-benzamide(L-1 and D-1) in a living/controlled chain growth manner. Polymerization kinetics of L-1 and D-1 indicated that L-1 preferentially polymerized over the antipode D-1 by a factor of 1.9. In block copolymerization of rac-1 using the poly-L-150 as the macroinitiator, the polymerization proceeded in enantiomer-selective manner. It was found that enantiomeric excess(ee) value of the recovered monomer increased with the monomer conversion and finally reached to the maximum of 34%. These results suggest this chiral phosphine complex exhibits enantiomer-selectivity for the polymerization of chiral allene derivative monomer.
基金supported by the University of Colorado Boulder。
文摘Single-ion conducting polymer electrolytes have attracted great attention as safe alternatives to liquid electrolytes in high energy density lithium-ion batteries.Herein,we report the first example of a crystalline anionic helical polymer as a single lithium-ion conducting solid polymer electrolyte(SPE).Single-crystal X-ray analysis shows that the polymer folds into densely packed double helices,with bundles of unidirectional negatively charged channels formed that can facilitate lithium-ion transportation.
基金This work was supported by the National Natural Science Foundation of China(51973011,52003022).
文摘Circularly polarized luminescence(CPL)-active nanomaterials have attracted tremendous attention.However,it is still a big challenge to conveniently fabricate multi-color and white CPL-active nanomaterials on a large scale.Herein,a simple and scalable approach to achieve the above goals is presented.Multicolor CPL-active nanofibers are fabricated from chiral helical substituted polyacetylene,achiral fluorescent dyes and polyacrylonitrile via uniaxial electrospinning;the highest luminescence dissymmetry factor(glum)of the resulting nanofibers can reach 10^(−2).Furthermore,white CPL-active nanofibers are obtained by coaxial electrospinning,in which the resulting core-shell structure has excellent adjustability and can be utilized to physically isolate different fluorescent dyes to reduce energy transfer efficiency;therefore,stable white CPL emissions can be achieved with high g_(lum) values up to 10^(−3).Notably,the prepared white-emission CPL nanofibrous films show bright white circularly polarized light when coated on UV chips,demonstrating their future application in constructing low-cost and flexible light-emitting devices such as circularly polarized light-emitting diodes.
基金supported by the National Science Foundation of China(nos.22071078 and 21722403)the Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)(no.2019TD-36).
文摘To understand the relationships between channel size and ion selectivity,we have developed a new type of artificial ion channel based on pore-forming helical polymers consisting of phenanthrolineoxadiazole units with a pore aperture 2.3A close to the diameter of the Na^(+)ion(2.04A).Successful preparation of high molecular weight helical polymers(HP1)gives rise to a 4.6 nm long artificial unimolecular transmembrane channel.The transport property of artificial channel HP1 was elaborately investigated by means of vesicle-based kinetic assay and symmetry/asymmetry bilayer membrane(BLM)experiments as well.These results unambiguously demonstrate that HP1 is a Na^(+)-selective channel with extremely high transport activity(EC_(50)=0.017 mol% relative to lipid).Moreover,the Na^(+)/K^(+)selectivity ratio of HP1 reaches 1.9,as determined by asymmetry BLM experiments.Owing to the narrowest 2.3A size constraint so far,HP1 transport naked Na^(+)ion across the membrane,which represents a different Na^(+)transport mode from that of natural Na^(+)channels,which transports partially hydrated Na^(+)ions during transmembrane conduction.This study provides crucial insights on the chemical basis of ion selectivity in the field of ion channels.
基金This work was financially supported by the NNSF of China (No. 20173063), the State Key Basic Research and Development Plan of China (001CB108906) and the NSF of Fujian Province (E0020001)
文摘A new zinc polymer, {Zn（O2CC12H8CO2）（H2O）}, or {Zn（DPHA）（H2O）}n （O2CC12H8CO2, DPHA = 1,1′ -biphenyl-2,2′-dicarboxylate dianion） has been synthesized under hydrothermal conditions. The crystal is of monoclinic, space group P21/c with a = 12.8418（5）, b = 5.9505（2）, c = 17.2989（5） A, β = 104.020（2）°, V = 1282.52（8） A^3, C14H10O5Zn, Mr= 323.61, Z = 4, Dc = 1.676 g/cm^3,μ = 1.930 mm^-1, F（000） = 656, R = 0.0766 and wR = 0.1871 for 1775 observed reflections （I 〉 2σ（I））. It consists of Zn2（DPHA）2（H2O）2 units, which are further extended into a one-dimensional double helical-chain polymer via Zn-O bonding. The hydrogen bonding interactions extend the helical chains into a two-dimensional layer structure.
