Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generat...Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense research.Effective progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and informatics.However,individual molecular machines are only capable of producing nanometer work and generally have only a single functionality.In order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new paradigm.In this review,we comprehensively discuss recent developments in the collective behaviors of molecular machines.In particular,collective behavior is divided into two paradigms.One is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional materials.The other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale operations.We discuss design strategies for both modes and focus on the modulation of features and properties.Subsequently,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.展开更多
An artificial molecular machine consists of molecule or substituent components jointed together in a specific way so that their mutual displacements could be initiated using appropriate outside stimuli. Such an abilit...An artificial molecular machine consists of molecule or substituent components jointed together in a specific way so that their mutual displacements could be initiated using appropriate outside stimuli. Such an ability of performing mechanical motions by consuming external energy has endowed these tiny machines with vast fascinating potential applications in areas such as actuators, manipulating atoms/molecules, drug delivery, molecular electronic devices, etc. To date, although vast kinds of molecular machine archetypes have been synthesized in facile ways, they are inclined to be defined as switches but not true machines in most cases because no useful work has been done during a working cycle. More efforts need to be devoted on the utilization and amplification of the nanoscale mechanical motions among synthetic molecular machines to accomplish useful tasks. Here we highlight some of the recent advances relating to molecular machines that can perform work on different length scales, ranging from microscopic levels to macroscopic ones.展开更多
Movements in molecular machines are usually diverse and coupled,but some of them are often implicit and hard to be observed in experiments.In the present work,the two-or three-dimensional free-energy landscapes charac...Movements in molecular machines are usually diverse and coupled,but some of them are often implicit and hard to be observed in experiments.In the present work,the two-or three-dimensional free-energy landscapes characterizing the coupled shutthng and other movements of a series of pH-triggered rotaxanes composed of a crown ether and an H-shaped axle with distinct number of phenyl rings(n=1-3)have been explored.The results show that although the calculated free-energy barriers against shutthng in the rotaxanes(n=2 and 3)change slightly,the move-ments coupled with the shutthng vary significantly with the axle length.At high pH,the shutthng in the rotaxane of n=2 is coupled with the isomerization of the wheel,while the shutthng in the one of n=3 is accompanied by both the isomerization and the rotation of the macrocycle.In addition,the crown ether imdenvent greater conlomiational change during shutthng at low pH compared to that at high pH.These results indicate that disentangling the coupled movements is important to reveal the underlying molecular mechanism of the shutthng.展开更多
Molecular switches that can undergo reversible switching between two or more different states in response to external stimuli have been used in the fabrication of various optoelectronic devices and smart materials for...Molecular switches that can undergo reversible switching between two or more different states in response to external stimuli have been used in the fabrication of various optoelectronic devices and smart materials for many decades, and also found many applications in sensing, molecular self-assembly and photo-controlled biological systems. Recently, mechanically interlocked molecules, such as rotaxanes and catenanes, and molecular rotary motors based on overcrowded alkenes have emerged as two new kinds of molecular switches. Some novel applications of above-mentioned molecular switches have been discovered. In this mini review, we mainly highlight noticeable achievements over the past decade in this field, and summarize the applications of new types of molecular switches, for instance, controlling the chiral space to regulate catalytic reaction as organocatalysts, controlling molecular motions, synthesizing a peptide in a sequence-specific manner and modulating the wettability of the self-assembled monolayers.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 guests(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
基金supported by National Key R&D Program of China(2018YFA0901700)National Natural Science Foundation of China(22278241)+1 种基金a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016)Department of Chemical Engineering-iBHE Joint Cooperation Fund.
文摘Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense research.Effective progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and informatics.However,individual molecular machines are only capable of producing nanometer work and generally have only a single functionality.In order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new paradigm.In this review,we comprehensively discuss recent developments in the collective behaviors of molecular machines.In particular,collective behavior is divided into two paradigms.One is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional materials.The other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale operations.We discuss design strategies for both modes and focus on the modulation of features and properties.Subsequently,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.
基金financially supported by the National Natural Science Foundation of China (21572063, 21372076)the Science Fund for Creative Research Groups (21421004)+1 种基金the Programme of Introducing Talents of Discipline to Universities (B16017)the Fundamental Research Funds for the Central Universities (222201717003)
文摘An artificial molecular machine consists of molecule or substituent components jointed together in a specific way so that their mutual displacements could be initiated using appropriate outside stimuli. Such an ability of performing mechanical motions by consuming external energy has endowed these tiny machines with vast fascinating potential applications in areas such as actuators, manipulating atoms/molecules, drug delivery, molecular electronic devices, etc. To date, although vast kinds of molecular machine archetypes have been synthesized in facile ways, they are inclined to be defined as switches but not true machines in most cases because no useful work has been done during a working cycle. More efforts need to be devoted on the utilization and amplification of the nanoscale mechanical motions among synthetic molecular machines to accomplish useful tasks. Here we highlight some of the recent advances relating to molecular machines that can perform work on different length scales, ranging from microscopic levels to macroscopic ones.
基金Supported by the National Natural Science Foundation of China(No.21773125)the Fundamental Research Funds for the Central Universities,China(No.63191743)+1 种基金the Natural Science Foundation of Tianjin,China(No.18JCYBJC2O5OO)the China Postdoctoral Science Foundation(No.bs6619012).
文摘Movements in molecular machines are usually diverse and coupled,but some of them are often implicit and hard to be observed in experiments.In the present work,the two-or three-dimensional free-energy landscapes characterizing the coupled shutthng and other movements of a series of pH-triggered rotaxanes composed of a crown ether and an H-shaped axle with distinct number of phenyl rings(n=1-3)have been explored.The results show that although the calculated free-energy barriers against shutthng in the rotaxanes(n=2 and 3)change slightly,the move-ments coupled with the shutthng vary significantly with the axle length.At high pH,the shutthng in the rotaxane of n=2 is coupled with the isomerization of the wheel,while the shutthng in the one of n=3 is accompanied by both the isomerization and the rotation of the macrocycle.In addition,the crown ether imdenvent greater conlomiational change during shutthng at low pH compared to that at high pH.These results indicate that disentangling the coupled movements is important to reveal the underlying molecular mechanism of the shutthng.
基金supported by the National Natural Science Foundation of China(21272073,21421004,21190033)the National Basic Research Program of China(2011CB808400)+1 种基金the Fok Ying Tong Education Foundation(121069)the Fundamental Research Funds for the Central Universities,and the Innovation Program of Shanghai Municipal Education Commission
文摘Molecular switches that can undergo reversible switching between two or more different states in response to external stimuli have been used in the fabrication of various optoelectronic devices and smart materials for many decades, and also found many applications in sensing, molecular self-assembly and photo-controlled biological systems. Recently, mechanically interlocked molecules, such as rotaxanes and catenanes, and molecular rotary motors based on overcrowded alkenes have emerged as two new kinds of molecular switches. Some novel applications of above-mentioned molecular switches have been discovered. In this mini review, we mainly highlight noticeable achievements over the past decade in this field, and summarize the applications of new types of molecular switches, for instance, controlling the chiral space to regulate catalytic reaction as organocatalysts, controlling molecular motions, synthesizing a peptide in a sequence-specific manner and modulating the wettability of the self-assembled monolayers.
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 guests(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.
