Molecular Ratchets and Kinetic Asymmetry: Giving Chemistry Direction

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(23)

Опубликована: Апрель 3, 2024

Abstract Over the last two decades ratchet mechanisms have transformed understanding and design of stochastic molecular systems—biological, chemical physical—in a move away from mechanical macroscopic analogies that dominated thinking regarding dynamics in 1990s early 2000s (e.g. pistons, springs, etc), to more scale‐relevant concepts underpin out‐of‐equilibrium research sciences today. Ratcheting has established nanotechnology as frontier for energy transduction metabolism, enabled reverse engineering biomolecular machinery, delivering insights into how molecules ‘walk’ track‐based synthesisers operate, acceleration reactions enables be transduced by catalysts (both motor proteins synthetic catalysts), dynamic systems can driven equilibrium through catalysis. The recognition biology, their invention systems, is proving significant areas diverse supramolecular chemistry, covalent DNA nanotechnology, polymer materials science, heterogeneous catalysis, endergonic synthesis, origin life, many other branches science. Put simply, give chemistry direction. Kinetic asymmetry, key feature ratcheting, counterpart structural asymmetry (i.e. chirality). Given ubiquity processes significance behaviour function it surely just fundamentally important. This Review charts recognition, development ratchets, focussing particularly on role which they were originally envisaged elements machinery. Different kinetically asymmetric are compared, consequences discussed. These archetypal examples demonstrate inexorably equilibrium, rather than relax towards it.

Язык: Английский

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Kinetic Asymmetry and Directionality of Nonequilibrium Molecular Systems

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(9)

Опубликована: Янв. 18, 2024

Abstract Scientists have long been fascinated by the biomolecular machines in living systems that process energy and information to sustain life. The first synthetic molecular rotor capable of performing repeated 360° rotations due a combination photo‐ thermally activated processes was reported 1999. progress designing different intervening years has remarkable, with several outstanding examples appearing last few years. Despite accomplishments, there remains confusion regarding fundamental design principles which motions molecules can be controlled, significant intellectual tension between mechanical chemical ways thinking about describing machines. A thermodynamically consistent analysis kinetics rotors pumps shows while light driven operate power‐stroke mechanism, kinetic asymmetry—the relative heights barriers—is sole determinant directionality catalysis Power‐strokes—the depths wells—play no role whatsoever determining sign directionality. These results, elaborated using trajectory thermodynamics nonequilibrium pump equality, show asymmetry governs response many non‐equilibrium phenomena.

Язык: Английский

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Artificial Molecular Ratchets: Tools Enabling Endergonic Processes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(47)

Опубликована: Авг. 7, 2023

Abstract Non‐equilibrium chemical systems underpin multiple domains of contemporary interest, including supramolecular chemistry, molecular machines, prebiotic and energy transduction. Experimental chemists are now pioneering the realization artificial that can harvest away from equilibrium. In this tutorial Review, we provide an overview ratchets: mechanisms enabling absorption environment. By focusing on mechanism type—rather than application domain or source—we offer a unifying picture seemingly disparate phenomena, which hope will foster progress in fascinating science.

Язык: Английский

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Dynamic covalent synthesis

Chemical Science, Год журнала: 2023, Номер 15(3), С. 879 - 895

Опубликована: Дек. 11, 2023

Dynamic covalent synthesis aims to precisely control the assembly of simple building blocks linked by reversible bonds generate a single, structurally complex, product. In recent years, considerable progress in programmability dynamic systems has enabled easy access broad range assemblies, including macrocycles, shape-persistent cages, unconventional foldamers and mechanically-interlocked species (catenanes, knots,

Язык: Английский

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Conformational selection accelerates catalysis by an organocatalytic molecular motor

Chem, Год журнала: 2023, Номер 10(3), С. 855 - 866

Опубликована: Ноя. 22, 2023

Conformational dynamics are increasingly recognized as an important contributor to enzyme catalysis but often overlooked in synthetic catalyst design. Here, we experimentally demonstrate faster by conformational selection caused stochastic interconversion of two conformations a catenane-based organocatalyst. The dependencies the reaction rates on relative positioning components during different stages catalytic cycle enable dynamic organocatalyst achieve order-of-magnitude rate accelerations over static or predominantly single-conformer analogs. acceleration results emergent property acting directionally rotating motor. In demonstrating that can overcome linear scaling relationships, these findings have implications for theories and artificial link between biased may suggest "motor molecules" could first arisen primitive form due prebiotic evolutionary pressure catalysis.

Язык: Английский

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Photoswitchable Imines Drive Dynamic Covalent Systems to Nonequilibrium Steady States

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(30), С. 20720 - 20727

Опубликована: Июль 18, 2024

Coupling a photochemical reaction to thermal exchange process can drive the latter nonequilibrium steady state (NESS) under photoirradiation. Typically, systems use separate motifs for photoresponse and equilibrium-related processes. Here, we show that photoswitchable imines fulfill both roles simultaneously, autonomously driving dynamic covalent system into NESS continuous light irradiation. We demonstrate this using transimination reactions, where

Язык: Английский

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Endergonic synthesis driven by chemical fuelling

Nature Synthesis, Год журнала: 2024, Номер 3(6), С. 707 - 714

Опубликована: Март 11, 2024

Abstract Spontaneous chemical reactions proceed energetically downhill to either a local or global minimum, limiting possible transformations those that are exergonic. Endergonic do not spontaneously and require an input of energy. Light has been used drive number deracemizations thermodynamically unfavourable bond-forming reactions, but is restricted substrates can absorb, directly indirectly, energy provided by photons. In contrast, anabolism involves uphill powered fuels. Here we report on the transduction from artificial fuel Diels–Alder reaction. Carboxylic acid catalysed carbodiimide-to-urea formation chemically orthogonal reaction diene dienophile, transiently brings functional groups into close proximity, causing otherwise prohibited cycloaddition in modest yield (15% after two fuelling cycles) with high levels regio- (>99%) stereoselectivity (92:8 exo : endo ). Kinetic asymmetry cycle ratchets away equilibrium distribution Diels–Alder:retro-Diels–Alder products. The driving endergonic occurs through ratchet mechanism (an information ratchet, depending synthetic protocol), reminiscent how molecular machines directionally bias motion. Ratcheting synthesis potential expand chemistry toolbox terms reactivity, complexity control.

Язык: Английский

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Kinetically Controlled and Nonequilibrium Assembly of Block Copolymers in Solution

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(28), С. 18781 - 18796

Опубликована: Июль 5, 2024

Covalent polymers are versatile macromolecules that have found widespread use in society. Contemporary methods of polymerization made it possible to construct sequence polymers, including block copolymers, with high precision. Such copolymers assemble solution when the blocks differing solubilities. This produces nano- and microparticles various shapes sizes. While is straightforward draw an analogy between such amphiphilic phospholipids, these two classes molecules show quite different assembly characteristics. In particular, often under kinetic control, thus producing nonequilibrium structures. leads a rich variety behaviors being observed copolymer assembly, as pathway dependence (e.g., thermal history), nonergodicity responsiveness. The dynamics polymer assemblies can be readily controlled using changes environmental conditions and/or integrating functional groups situated on external chemical reactions. perspective highlights control both pervasive useful attribute mechanics assembly. Recent examples highlighted order toggling static dynamic behavior used generate, manipulate dismantle states. New kinetics will provide endless unanticipated applications materials science, biomimicry medicine.

Язык: Английский

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The End of the Beginning of Mechanical Stereochemistry

Accounts of Chemical Research, Год журнала: 2024, Номер 57(12), С. 1696 - 1708

Опубликована: Июнь 3, 2024

ConspectusStereochemistry has played a key role in the development of synthetic chemistry for simple reason that function and properties most molecules, from medicine to materials science, depend on their shape thus stereoisomer used. However, despite potential rotaxanes catenanes display unusual forms stereochemistry being identified as early 1961, this aspect mechanical bond remained underexplored underexploited; until 2014 it was only possible access chiral whose stereoisomerism is solely attributable using stationary phase high performance liquid chromatography, which limited production scale inhibited investigation applications. Furthermore, stereogenic units such molecules analogues were often poorly described, made hard fully articulate both what had been achieved field problems left solve. Relatively recently, methods selectively have developed, making these intriguing structures available study range prototypical applications including catalysis, sensing, luminophores.In Account, we briefly discuss history stereochemistry, beginning 1961 when first identified, before defining how arises structural point view. Building this, stereochemical arguments, confirm complete set unique two-component finally categorized unambiguously, with last 2024. After pausing some curiosities arise contain covalent units, due co-conformational movement, use our framework summarize efforts develop conceptually general approaches [2]catenanes [2]rotaxanes containing all units. In particular, highlight nature unit affects strategies stereoselective synthesis. We finish by highlighting recent chemical interlocked rely discussing future directions challenges.Taken together, propose transition make stereopurity clearly articulated methodological concepts suggests maturing. Thus, are now coming end stereochemistry. The stage play functional areas, indeed any or physical application where control over molecular required.

Язык: Английский

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Stepwise Operation of a Molecular Rotary Motor Driven by an Appel Reaction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(7), С. 4467 - 4472

Опубликована: Фев. 6, 2024

To date, only a small number of chemistries and chemical fueling strategies have been successfully used to operate artificial molecular motors. Here, we report the 360° directionally biased rotation phenyl groups about C–C bond, driven by stepwise Appel reaction sequence. The motor molecule consists biaryl-embedded phosphine oxide phenol, in which full around biaryl bond is blocked P–O oxygen atom on rotor being too bulky pass stator. Treatment with SOCl2 forms cyclic oxyphosphonium salt (removing oxide), temporarily linking Conformational exchange via ring flipping then allows stator twist back forth past previous limit rotation. Subsequently, opening tethered intermediate chiral alcohol occurs preferentially through nucleophilic attack one face. Thus, original reformed net directional over course two-step Each repetition SOCl2–chiral additions generates another Using same sequence derivative that atropisomers rather than fully rotating results enantioenrichment, suggesting that, average, rotates "wrong" direction once every three cycles. interconversion oxides form temporary tethers enable rotational barrier be overcome adds available for generating chemically fueled kinetic asymmetry systems.

Язык: Английский

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