Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-co...Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-complexation from P1 or P2, whereas, concentration-dependent pseudorotaxane structures were generated by P3 which bearing more flexible side chain. Interestingly, the obtained pseudo[1]rotaxanes exhibited a dynamic fast assembly process upon adding NaBF4, resulting in the formation of Na＋-induced pseudorotaxanes.展开更多
The series of salen-bridged bis-pillar[1]arenes were conveniently prepared by condensation reaction of5,5'-methylenebis(2-hydroxybenzalde hyde)or 5,5'-(propane-2,2-diyl)bis(2-hydroxybenzaldehyde)with mono-amid...The series of salen-bridged bis-pillar[1]arenes were conveniently prepared by condensation reaction of5,5'-methylenebis(2-hydroxybenzalde hyde)or 5,5'-(propane-2,2-diyl)bis(2-hydroxybenzaldehyde)with mono-amido-functionalized pillar[5]arenes containing different terminal aminoalkyl groups in refluxing ethanol.The^1H NMR and 2D-NOESY spectra indicated that the salen-bridged bis-pillar[5]arenes with longer allcylene linker(n=3,4,6)formed the fascinating bis-[1]rotaxanes,while the salenbridged bis-pillar[5]arenes with short hydrazine and ethylenediamino linker(n=0,2)predominately existed in free form.The single crystal structure of the bis-pillar[5]are ne ambiguously indicated that two propylenediamino linker inserted in to two cavities of pillar[5]arene to form a novel bis-[1]rotaxanes.展开更多
Four pillar[5]arene based[3]rotaxanes(1-4)involving two 1,4-diethoxypillar[5]arene(DEP5)rings and a dumbbell-shaped component were successfully synthesized.The dumbbell-shape molecules contain one longer bridge,two tr...Four pillar[5]arene based[3]rotaxanes(1-4)involving two 1,4-diethoxypillar[5]arene(DEP5)rings and a dumbbell-shaped component were successfully synthesized.The dumbbell-shape molecules contain one longer bridge,two triazole sites and two multicomponent stoppers.After threading DEP5 rings with linear vips(G1-G4)which contain two benzaldehyde units,the base catalyzed three-component reaction of dimedone,malononitrile and benzaldehyde was performed to construct the stoppers and connected the pseudorotaxanes with stoppers to generate 1-4.The structures of[3]rotaxanes and their self-assembly behaviors were characterized by 1 H NMR,13C NMR,NOESY,HR-ESI-MS,DLS and TEM technologies.We hope that pillar[5]arene based[3]rotaxanes may have potential applications in drug delivery systems and molecular devices.展开更多
Series of azobenzene-bridged pillar[5]arene-based [3]rotaxanes with different alkyl chain length of vip molecules were constructed by threading-endcapping method with alkylenetriazole as axile and tetrahydrochromene...Series of azobenzene-bridged pillar[5]arene-based [3]rotaxanes with different alkyl chain length of vip molecules were constructed by threading-endcapping method with alkylenetriazole as axile and tetrahydrochromene as endcapping group.The encapsulation of pillar[5]arenes were proved by highresolution mass,^(1) H NMR and NOESY spectra.The photo-responsive property were examined by irradiation of the synthesized [3]rotaxanes with 365 nm and blue light LED,which caused trans to cis and cis to trans isomerization,respectively.Irradiation of corresponding model vip compounds without pillar[5]arene encapsulation resulted in near completely trans to cis and cis to trans isomerization,indicating the existence of pillar[5]arenes is the determining factor for the comprised photo isomerization efficiency.展开更多
Several cyclodextrin-cucurbit[6]uril-cowheeled [4]rotaxanes were synthesized through the cucurbit[6]uril-templated azide-alkyne 1,3-dipolar cycloaddition. The intramolecular interaction between the aromatic axle and t...Several cyclodextrin-cucurbit[6]uril-cowheeled [4]rotaxanes were synthesized through the cucurbit[6]uril-templated azide-alkyne 1,3-dipolar cycloaddition. The intramolecular interaction between the aromatic axle and the capping groups of cyclodextrin moieties was investigated by UV-vis, fluorescence,circular dichroism and NMR spectroscopic studies. The rotational kinetic of the wheel around the axle can be manipulated by adjusting the temperature. The capping group apparently slowed down the rotation of the wheel, playing a role of the brake, and lowering the temperature can stop the rotation of the wheel on the NMR timescale.展开更多
As a promising imaging technology,the low sensitivity of fluorine-19 magnetic resonance imaging(^(19)F MRI)severely hinders its biomedical applications.Herein,we have developed an unprecedented rotaxanebased strategy ...As a promising imaging technology,the low sensitivity of fluorine-19 magnetic resonance imaging(^(19)F MRI)severely hinders its biomedical applications.Herein,we have developed an unprecedented rotaxanebased strategy to improve the sensitivity of^(19)F MRI agents.By threading the fluorinated macrocycle into2-blade pinwheel[2]rotaxanes,the^(19)F longitudinal relaxation rate R1was dramatically increased,resulting in a significant^(19)F MRI signal intensity enhancement of up to 79%.Through comparative molecular dynamics studies using a series of solution and solid-state^(1)H/^(19)F nuclear magnetic resonance(^(1)H/^(19)F NMR)and molecular dynamics simulations,it was found that the formation of mechanical bonds dramatically restricts the motion of the wheel fluorines and thus increasing the R1for higher^(19)F MRI sensitivity.Besides a novel strategy for improving^(19)F MRI sensitivity,this study has established^(19)F NMR/MRI as a valuable technology for monitoring the molecular dynamics of rotaxanes,which may shed new light on high-performance^(19)F MRI agents and molecular devices.展开更多
Two strategies for the design of new pillar[5]arene-based mechanically self-interlocked molecules (MSMs) are reported here. The first strategy is based on the construction of an intermediate pseudo[1]rotaxane followed...Two strategies for the design of new pillar[5]arene-based mechanically self-interlocked molecules (MSMs) are reported here. The first strategy is based on the construction of an intermediate pseudo[1]rotaxane followed by the desired bis-[l]rotaxane. The other one is based on the construction of the desired bis-[1]rotaxane directly via a condensation reaction through host-vip interactions between a mono-functionalized pillar[5]arene and the axle. The newly synthesized bis-[1]rotaxane BR was characterized by ~1H NMR, ^(13)C NMR, 2D NMRs (~1H-^(13)C HSQC,~1H-~1H COSY and NOESY) and LC-ESI-MS,which indicated compound BR displayed an self-interlocked structure in CDCl_3. Surprisingly, the results of SEM, TEM and DLS showed that the compound BR could assemble into spherical nanoparticles in MeOH.展开更多
The condensation reaction ofω-aminoalkyleneamide-functionalized pillar[5]arenes with 2-(4-([2,2’:6’,2〃-terpyridin]-4’-yl)phenoxy)acetic acid or 4-(4-([2,2’:6’,2"-terpyridin]-4’-yl)phenoxy)butanoic acid in...The condensation reaction ofω-aminoalkyleneamide-functionalized pillar[5]arenes with 2-(4-([2,2’:6’,2〃-terpyridin]-4’-yl)phenoxy)acetic acid or 4-(4-([2,2’:6’,2"-terpyridin]-4’-yl)phenoxy)butanoic acid in dry chloroform at room temperature under the catalysis of HOBT/EDCl resulted in novel pillar[5]arene diamido-bridged terpyridine derivatives.~1 H NMR and 2 D NOESY spectra clearly indicated that the interesting[1]rotaxanes were formed by longer alkylene such as propylene,butylene and hexylenediamido chains threading into the cavity of the pillar[5]arene and with larger terpyridine acting as the stopper.However,the shorter ethylenediamido chain only exists outer of cavity of pillar[5]arene and the molecule exist on free form.展开更多
Based on a[2]rotaxane precursor with exchangeable pentafluorophenyl ester stoppers,a new wheelassembling approach has been successfully developed for the precise sequence control of hetero[3]rotaxanes,leading to the f...Based on a[2]rotaxane precursor with exchangeable pentafluorophenyl ester stoppers,a new wheelassembling approach has been successfully developed for the precise sequence control of hetero[3]rotaxanes,leading to the facile and efficient synthesis of both sequence isomers of hetero[3]rotaxanes.More importantly,taking advantage of the chirality retention along with the wheel-assembling process,corresponding sequence isomers of chiral AIEgenfunctionalized hetero[3]rotaxanes were further precisely synthesized.Impressively,the resultant hetero[3]rotaxanes revealed remarkable sequencedependent aggregation-induced emission(AIE)behavior and circularly polarized luminescence performance with large dissymmetry factors up to 0.012,highlighting the great power of the newly coined sequence engineering concept in developing novel AIE-active chiroptical materials.This proof-ofconcept study lays the foundation for investigation of the structure-property relationships of heterorotaxanes that can further direct the rational design and precise synthesis of sequence-defined heterorotaxanes with desirable properties for practical applications.展开更多
We have developed a rotaxane-based mechanophore system that is capable of breaking a mechanical bond and releasing small molecules via force-triggered rotaxane disassembly.In this design,a cyclobutane mechanophore was...We have developed a rotaxane-based mechanophore system that is capable of breaking a mechanical bond and releasing small molecules via force-triggered rotaxane disassembly.In this design,a cyclobutane mechanophore was fused to the ring component of a rotaxane,constructed through a template-mediated synthesis in high yields.Upon opening the ring component,the rotaxane disassembled to release the axle molecule.We successfully demonstrated and quantified the force-triggered release of the axlemolecule in both solution and solid-state samples.展开更多
One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4-dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor-acceptor interaction and/or intermo...One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4-dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor-acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotaxane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF6 was assembled by using donor-acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated.展开更多
Crown ether usually plays the role of macrocyclic host in supramolecular chemistry, but here the crown ether is also utilized as the stoppers in rotaxanes. In this work, we designed and synthesized two [3]rotaxanes co...Crown ether usually plays the role of macrocyclic host in supramolecular chemistry, but here the crown ether is also utilized as the stoppers in rotaxanes. In this work, we designed and synthesized two [3]rotaxanes containing four crown ether components by using an approach of template-directed clipping reaction, of which, two crown ether components were employed as the macrocyclic hosts to assemble the mechanically interlocked framework while another two crown ether units located on the two ends of ammonium template acting as the stoppering groups of rotaxanes. Their self-assembling process was monitored by the 1H NMR and one of the single crystal structures of [3]rotaxane was obtained.展开更多
A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,h...A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,has been synthesized.This multi-stimuli-responsive[3]rotaxane exhibits unique molecular motion,with the macrocycles shuttling along the axle in response to acid-base reactions,temperature changes,solvent variations,and light irradiation.The molecular shuttle and reversibility were investigated by^(1)H NMR,2D NOESY,HRESI-MS,and UV-vis spectroscopy.This study provides a rare example of a higher order rotaxane with multi-stimuli responsiveness,highlighting its potential for multi-state control over the motion of interlocked rings on an axle.The ability to manipulate the molecular motion of the macrocycles through various external triggers offers insights for future developments in molecular machinery and adaptive materials.展开更多
Herein,an alkyne-terminated acid/base responsive amphiphilic [2]rotaxane shuttle was synthesized,and then modified onto the glass surface through “click” reaction.The XPS N 1s spectrum and contactangle measurement w...Herein,an alkyne-terminated acid/base responsive amphiphilic [2]rotaxane shuttle was synthesized,and then modified onto the glass surface through “click” reaction.The XPS N 1s spectrum and contactangle measurement were performed to prove the successful immobilization.The amphiphilic [2]rotaxane functionalized surface presented controllable wettability responding to external acid-base stimuli.This bistable rotaxane modified material system promoted the practical application of molecular machines.展开更多
Molecular orbital PM3 calculation was performed on the complexation of cyclobis(paraquat-p-phenylene) with a number of 1,4-disubstituted benzenes and biphenyl derivatives. A fair correlation was found between the PM3 ...Molecular orbital PM3 calculation was performed on the complexation of cyclobis(paraquat-p-phenylene) with a number of 1,4-disubstituted benzenes and biphenyl derivatives. A fair correlation was found between the PM3 calculated binding energies and the experimental ones, which enabled the PM3 calculation to predict thc experimental binding energies for a number of important complexes. A good structure-activity relationship was also found between the PM3 calculated binding energies and the substituent molar refraction R-m and Hammett constants. indicating that the van der Waals force and the electronic interactions constituted the major driving forces for the complexation of cyclobis(paraquat-p-phenylene).展开更多
A [3]rotaxane I involving two naphtho-21-crown-7 （N21 C7） rings and a dumbbell-shaped component 4 was synthesized. The dumbbell-shape molecule 4 contains one viologen nucleus, two secondary alkyl ammonium sites and ...A [3]rotaxane I involving two naphtho-21-crown-7 （N21 C7） rings and a dumbbell-shaped component 4 was synthesized. The dumbbell-shape molecule 4 contains one viologen nucleus, two secondary alkyl ammonium sites and two phenyl stoppers. After threading the N21C7 ring with the thread-like ammonium vip 3, the copper（l）-catalyzed Huisgen alkyne-azide 1,3-dipolar cycloaddition （CuAAC ＂click＂ reaction）, was performed to connect the pseudorotaxanes with viologen unit 2 and generate 1. Through treating the [3]rotaxane by the base and acid circularly, the two N21 C7 rings can make shuttling motion along the axle. Meanwhile the distance between the electron-deficient viologen unit and the electron-rich naphthol group can be adjusted precisely along with a remarkable intramolecular charge- transfer （CT） behavior.展开更多
A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion...A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion of the functionalized rotaxane system.The UV-vis,^(1) H NMR and PL spectroscopic data clearly demonstrated that the DPAC ring was interlocked onto the thread and the fluorescence intensity of the DPAC unit in the macrocycle was effectively regulated by the location change of the macrocycle along the thread under acid/base stimulation,which was attributed to the modulation of the intramolecular photo-induced electron transfer between the DPAC unit and the methyltriazole(MTA)unit.This bistable rotaxane system containing a conformation-adaptive fluorophore unit in the macrocycle moiety opens an alternative way to design functional bistable mechanically interlocked molecules.展开更多
The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a ...The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.21472089,21572101)the National Natural Science Foundation of Jiangsu(No.BK20140595)
文摘Mono-alkyl-functionalized pillar[5]arenes PI, P2, and P3 were synthesized by click reaction, which exhibited different self-assembly behavior in polar solvent DMSO. Stable pseudo[ 1 ]rotaxane was formed by the self-complexation from P1 or P2, whereas, concentration-dependent pseudorotaxane structures were generated by P3 which bearing more flexible side chain. Interestingly, the obtained pseudo[1]rotaxanes exhibited a dynamic fast assembly process upon adding NaBF4, resulting in the formation of Na＋-induced pseudorotaxanes.
基金financial support by the National Natural Science Foundation of China(Nos.21372192,21871227)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The series of salen-bridged bis-pillar[1]arenes were conveniently prepared by condensation reaction of5,5'-methylenebis(2-hydroxybenzalde hyde)or 5,5'-(propane-2,2-diyl)bis(2-hydroxybenzaldehyde)with mono-amido-functionalized pillar[5]arenes containing different terminal aminoalkyl groups in refluxing ethanol.The^1H NMR and 2D-NOESY spectra indicated that the salen-bridged bis-pillar[5]arenes with longer allcylene linker(n=3,4,6)formed the fascinating bis-[1]rotaxanes,while the salenbridged bis-pillar[5]arenes with short hydrazine and ethylenediamino linker(n=0,2)predominately existed in free form.The single crystal structure of the bis-pillar[5]are ne ambiguously indicated that two propylenediamino linker inserted in to two cavities of pillar[5]arene to form a novel bis-[1]rotaxanes.
基金supported by the National Natural Science Foundation of China(Nos.21871227,21801139)Natural Science Foundation of Jiangsu Province(No.BK20180942)Natural Science Foundation of Nantong University for High-Level Talent(No.03083004)。
文摘Four pillar[5]arene based[3]rotaxanes(1-4)involving two 1,4-diethoxypillar[5]arene(DEP5)rings and a dumbbell-shaped component were successfully synthesized.The dumbbell-shape molecules contain one longer bridge,two triazole sites and two multicomponent stoppers.After threading DEP5 rings with linear vips(G1-G4)which contain two benzaldehyde units,the base catalyzed three-component reaction of dimedone,malononitrile and benzaldehyde was performed to construct the stoppers and connected the pseudorotaxanes with stoppers to generate 1-4.The structures of[3]rotaxanes and their self-assembly behaviors were characterized by 1 H NMR,13C NMR,NOESY,HR-ESI-MS,DLS and TEM technologies.We hope that pillar[5]arene based[3]rotaxanes may have potential applications in drug delivery systems and molecular devices.
基金supported by the National Natural Science Foundation of China(Nos.21372192,21871227)the Natural Science Foundation of Jiangsu Province(No.BK20190905)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Series of azobenzene-bridged pillar[5]arene-based [3]rotaxanes with different alkyl chain length of vip molecules were constructed by threading-endcapping method with alkylenetriazole as axile and tetrahydrochromene as endcapping group.The encapsulation of pillar[5]arenes were proved by highresolution mass,^(1) H NMR and NOESY spectra.The photo-responsive property were examined by irradiation of the synthesized [3]rotaxanes with 365 nm and blue light LED,which caused trans to cis and cis to trans isomerization,respectively.Irradiation of corresponding model vip compounds without pillar[5]arene encapsulation resulted in near completely trans to cis and cis to trans isomerization,indicating the existence of pillar[5]arenes is the determining factor for the comprised photo isomerization efficiency.
基金support of this work by the National Natural Science Foundation of China (Nos. 21871194, 21572142, 21372165, 21402129 and 21402110)National Key Research and Development Program of China(No. 2017YFA0505903)+1 种基金Science & Technology Department of Sichuan Province(No. 2017SZ0021)Comprehensive Training Platform of Specialized Laboratory, College of Chemistry, Sichuan university
文摘Several cyclodextrin-cucurbit[6]uril-cowheeled [4]rotaxanes were synthesized through the cucurbit[6]uril-templated azide-alkyne 1,3-dipolar cycloaddition. The intramolecular interaction between the aromatic axle and the capping groups of cyclodextrin moieties was investigated by UV-vis, fluorescence,circular dichroism and NMR spectroscopic studies. The rotational kinetic of the wheel around the axle can be manipulated by adjusting the temperature. The capping group apparently slowed down the rotation of the wheel, playing a role of the brake, and lowering the temperature can stop the rotation of the wheel on the NMR timescale.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0540000)the National Key R&D Program of China(No.2018YFA0704000)+2 种基金the National Natural Science Foundation of China(Nos.22327901,22077098,U21A20392,21921004,and 82127802)the Knowledge Innovation Program of WuhanBasic Research(No.2022020801010137)support from the Youth Innovation Promotion Association and the Young Top-notch Talent Cultivation Program。
文摘As a promising imaging technology,the low sensitivity of fluorine-19 magnetic resonance imaging(^(19)F MRI)severely hinders its biomedical applications.Herein,we have developed an unprecedented rotaxanebased strategy to improve the sensitivity of^(19)F MRI agents.By threading the fluorinated macrocycle into2-blade pinwheel[2]rotaxanes,the^(19)F longitudinal relaxation rate R1was dramatically increased,resulting in a significant^(19)F MRI signal intensity enhancement of up to 79%.Through comparative molecular dynamics studies using a series of solution and solid-state^(1)H/^(19)F nuclear magnetic resonance(^(1)H/^(19)F NMR)and molecular dynamics simulations,it was found that the formation of mechanical bonds dramatically restricts the motion of the wheel fluorines and thus increasing the R1for higher^(19)F MRI sensitivity.Besides a novel strategy for improving^(19)F MRI sensitivity,this study has established^(19)F NMR/MRI as a valuable technology for monitoring the molecular dynamics of rotaxanes,which may shed new light on high-performance^(19)F MRI agents and molecular devices.
文摘Two strategies for the design of new pillar[5]arene-based mechanically self-interlocked molecules (MSMs) are reported here. The first strategy is based on the construction of an intermediate pseudo[1]rotaxane followed by the desired bis-[l]rotaxane. The other one is based on the construction of the desired bis-[1]rotaxane directly via a condensation reaction through host-vip interactions between a mono-functionalized pillar[5]arene and the axle. The newly synthesized bis-[1]rotaxane BR was characterized by ~1H NMR, ^(13)C NMR, 2D NMRs (~1H-^(13)C HSQC,~1H-~1H COSY and NOESY) and LC-ESI-MS,which indicated compound BR displayed an self-interlocked structure in CDCl_3. Surprisingly, the results of SEM, TEM and DLS showed that the compound BR could assemble into spherical nanoparticles in MeOH.
基金financially supported by the National Natural Science Foundation of China (No.21871227)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The condensation reaction ofω-aminoalkyleneamide-functionalized pillar[5]arenes with 2-(4-([2,2’:6’,2〃-terpyridin]-4’-yl)phenoxy)acetic acid or 4-(4-([2,2’:6’,2"-terpyridin]-4’-yl)phenoxy)butanoic acid in dry chloroform at room temperature under the catalysis of HOBT/EDCl resulted in novel pillar[5]arene diamido-bridged terpyridine derivatives.~1 H NMR and 2 D NOESY spectra clearly indicated that the interesting[1]rotaxanes were formed by longer alkylene such as propylene,butylene and hexylenediamido chains threading into the cavity of the pillar[5]arene and with larger terpyridine acting as the stopper.However,the shorter ethylenediamido chain only exists outer of cavity of pillar[5]arene and the molecule exist on free form.
基金support by the National Natural Science Foundation of China(grant nos.92356307 and 22001073)the Natural Science Foundation of Shanghai(grant no.23ZR1419600)+3 种基金support by the National Natural Science Foundation of China(grant no.92056203)the Science and Technology Commission of Shanghai Municipality(grant no.21520710200)the National Key R&D Program of China(grant no.2021YFA1501600)support by the National Natural Science Foundation of China(grant no.22201077).
文摘Based on a[2]rotaxane precursor with exchangeable pentafluorophenyl ester stoppers,a new wheelassembling approach has been successfully developed for the precise sequence control of hetero[3]rotaxanes,leading to the facile and efficient synthesis of both sequence isomers of hetero[3]rotaxanes.More importantly,taking advantage of the chirality retention along with the wheel-assembling process,corresponding sequence isomers of chiral AIEgenfunctionalized hetero[3]rotaxanes were further precisely synthesized.Impressively,the resultant hetero[3]rotaxanes revealed remarkable sequencedependent aggregation-induced emission(AIE)behavior and circularly polarized luminescence performance with large dissymmetry factors up to 0.012,highlighting the great power of the newly coined sequence engineering concept in developing novel AIE-active chiroptical materials.This proof-ofconcept study lays the foundation for investigation of the structure-property relationships of heterorotaxanes that can further direct the rational design and precise synthesis of sequence-defined heterorotaxanes with desirable properties for practical applications.
基金This work was supported by the U.S.Army Research Office(grant no.W911NF-15-1-0525)J.Y.was partly supported by a Stanford Graduate Fellowship.Single-crystal X-ray diffraction experiments were performed at beamline 12.2.1 at the advanced light source(ALS).The ALS is supported by the Director,Office of Science,Office of Basic Energy Science,of the U.S.Department of Energy(contract no.DE-AC02-05CH11231).
文摘We have developed a rotaxane-based mechanophore system that is capable of breaking a mechanical bond and releasing small molecules via force-triggered rotaxane disassembly.In this design,a cyclobutane mechanophore was fused to the ring component of a rotaxane,constructed through a template-mediated synthesis in high yields.Upon opening the ring component,the rotaxane disassembled to release the axle molecule.We successfully demonstrated and quantified the force-triggered release of the axlemolecule in both solution and solid-state samples.
基金Project supported by the National Natural Science Foundation of China(Nos.20172069,90206005)and the Major State Basic Research Development Program(No.G200078101).
文摘One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4-dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor-acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotaxane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF6 was assembled by using donor-acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated.
基金The authors acknowledge financial support from Na- tional Natural Science Foundation of China （Nos. 21676113, 21402057, 21472059）, Youth Chen-Guang Project of Wuhan （No. 2016070204010098） the Minis- try-Province Jointly Constructed Base for State Key Lab-Shenzhen Key Laboratory of Chemical Biology, Shenzhen self-determined research funds of CCNU from the Colleges＇ Basic Research and Operation of MOE （No. CCNU16A02004）.
文摘Crown ether usually plays the role of macrocyclic host in supramolecular chemistry, but here the crown ether is also utilized as the stoppers in rotaxanes. In this work, we designed and synthesized two [3]rotaxanes containing four crown ether components by using an approach of template-directed clipping reaction, of which, two crown ether components were employed as the macrocyclic hosts to assemble the mechanically interlocked framework while another two crown ether units located on the two ends of ammonium template acting as the stoppering groups of rotaxanes. Their self-assembling process was monitored by the 1H NMR and one of the single crystal structures of [3]rotaxane was obtained.
基金supported by the National Natural Science Foundation of China(No.22271202 to L.Yuan,No.22201193 to X.Li)the Sichuan Science and Technology Program(No.2023NSFSC0109 to X.Li)+2 种基金the Fundamental Research Funds for the Central Universities and the Hundred Talent Program of Sichuan University(No.YJ2021158 to X.Li)Sichuan University Interdisciplinary Innovation Fund(X.Li)Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.SKLSSM2024037)。
文摘A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,has been synthesized.This multi-stimuli-responsive[3]rotaxane exhibits unique molecular motion,with the macrocycles shuttling along the axle in response to acid-base reactions,temperature changes,solvent variations,and light irradiation.The molecular shuttle and reversibility were investigated by^(1)H NMR,2D NOESY,HRESI-MS,and UV-vis spectroscopy.This study provides a rare example of a higher order rotaxane with multi-stimuli responsiveness,highlighting its potential for multi-state control over the motion of interlocked rings on an axle.The ability to manipulate the molecular motion of the macrocycles through various external triggers offers insights for future developments in molecular machinery and adaptive materials.
基金supported by the National Natural Science Foundation of China(Nos.21901063,U20041101)Young Talents Personnel Fund of Henan Agricultural University(No.30500604)Key Science and Technology Foundation of Henan Province(Nos.242102230178,232102310379)。
文摘Herein,an alkyne-terminated acid/base responsive amphiphilic [2]rotaxane shuttle was synthesized,and then modified onto the glass surface through “click” reaction.The XPS N 1s spectrum and contactangle measurement were performed to prove the successful immobilization.The amphiphilic [2]rotaxane functionalized surface presented controllable wettability responding to external acid-base stimuli.This bistable rotaxane modified material system promoted the practical application of molecular machines.
基金the NSFC. We also thank Prof. J. F. Stoddart for providing us the crystalline structure of 14+.
文摘Molecular orbital PM3 calculation was performed on the complexation of cyclobis(paraquat-p-phenylene) with a number of 1,4-disubstituted benzenes and biphenyl derivatives. A fair correlation was found between the PM3 calculated binding energies and the experimental ones, which enabled the PM3 calculation to predict thc experimental binding energies for a number of important complexes. A good structure-activity relationship was also found between the PM3 calculated binding energies and the substituent molar refraction R-m and Hammett constants. indicating that the van der Waals force and the electronic interactions constituted the major driving forces for the complexation of cyclobis(paraquat-p-phenylene).
基金the National Basic Research Program of China(973 Program,No.2011CB932500)the National Natural Science Foundation of China(Nos.20932004 and 20972077) for financial support
文摘A [3]rotaxane I involving two naphtho-21-crown-7 （N21 C7） rings and a dumbbell-shaped component 4 was synthesized. The dumbbell-shape molecule 4 contains one viologen nucleus, two secondary alkyl ammonium sites and two phenyl stoppers. After threading the N21C7 ring with the thread-like ammonium vip 3, the copper（l）-catalyzed Huisgen alkyne-azide 1,3-dipolar cycloaddition （CuAAC ＂click＂ reaction）, was performed to connect the pseudorotaxanes with viologen unit 2 and generate 1. Through treating the [3]rotaxane by the base and acid circularly, the two N21 C7 rings can make shuttling motion along the axle. Meanwhile the distance between the electron-deficient viologen unit and the electron-rich naphthol group can be adjusted precisely along with a remarkable intramolecular charge- transfer （CT） behavior.
基金supported by the National Natural Science Foundation of China(Nos.22025503,21790361 and 21871084)Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Program of Introducing Talents of Discipline to Universities(No.B16017)the Shanghai Science and Technology Committee(No.17520750100)funding from China Postdoctoral Science Foundation funded project(No.J100–5R-20130)。
文摘A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion of the functionalized rotaxane system.The UV-vis,^(1) H NMR and PL spectroscopic data clearly demonstrated that the DPAC ring was interlocked onto the thread and the fluorescence intensity of the DPAC unit in the macrocycle was effectively regulated by the location change of the macrocycle along the thread under acid/base stimulation,which was attributed to the modulation of the intramolecular photo-induced electron transfer between the DPAC unit and the methyltriazole(MTA)unit.This bistable rotaxane system containing a conformation-adaptive fluorophore unit in the macrocycle moiety opens an alternative way to design functional bistable mechanically interlocked molecules.
基金supported by the National Natural Science Foundation of China (Nos. 21901063, U20041101)Young Talents Personnel Fund of Henan Agricultural University (No. 30500604)。
文摘The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.
