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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Photoswitchable imines: aryliminopyrazoles quantitatively convert to long-lived Z-isomers with visible light

Chemical Science, Год журнала: 2024, Номер 15(11), С. 3872 - 3878

Опубликована: Янв. 1, 2024

Simple structural modifications significantly boost the photochromic performance of imine-based photoswitches. This work lays a foundation for exploring new motifs in light-addressable dynamic combinatorial chemistry.

Язык: Английский

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Transducing chemical energy through catalysis by an artificial molecular motor

Nature, Год журнала: 2025, Номер 637(8046), С. 594 - 600

Опубликована: Янв. 15, 2025

Abstract Cells display a range of mechanical activities generated by motor proteins powered through catalysis 1 . This raises the fundamental question how acceleration chemical reaction can enable energy released from that to be transduced (and, consequently, work done) molecular catalyst 2–7 Here we demonstrate molecular-level transduction force 8 in form contraction and re-expansion cross-linked polymer gel driven directional rotation artificial catalysis-driven 9 motors. Continuous 360° rotor about stator motor-molecules incorporated polymeric framework twists chains network around one another. progressively increases writhe tightens entanglements, causing macroscopic approximately 70% its original volume. The subsequent addition opposite enantiomer fuelling system powers reverse direction, unwinding entanglements re-expand. Continued twisting strands new direction causes re-contract. In actuation, motor-molecule produces other physical outcomes, including changes Young modulus storage modulus—the latter is proportional increase strand crossings resulting rotation. experimental demonstration against load synthetic organocatalyst, mechanism 6 , informs both debate 3,5,7 surrounding generation biological motors design principles 6,10–14 for nanotechnology.

Язык: Английский

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Using Catalysis to Drive Chemistry Away from Equilibrium: Relating Kinetic Asymmetry, Power Strokes, and the Curtin–Hammett Principle in Brownian Ratchets

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(44), С. 20153 - 20164

Опубликована: Окт. 26, 2022

Chemically fueled autonomous molecular machines are catalysis-driven systems governed by Brownian information ratchet mechanisms. One fundamental principle behind their operation is kinetic asymmetry, which quantifies the directionality of motors. However, it difficult for synthetic chemists to apply this concept design because asymmetry usually introduced in abstract mathematical terms involving experimentally inaccessible parameters. Furthermore, two seemingly contradictory mechanisms have been proposed chemically driven machines: and power stroke This Perspective addresses both these issues, providing accessible useful principles machinery. We relate Curtin–Hammett using a rotary motor kinesin walker as illustrative examples. Our approach describes motors mechanism but pinpoints chemical gating strokes tunable elements that can affect asymmetry. explain why consistent with previous ones outline conditions where be elements. Finally, we discuss role information, used different meanings literature. hope will broad range chemists, clarifying parameters usefully controlled synthesis related systems. It may also aid more comprehensive interdisciplinary understanding biomolecular

Язык: Английский

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The role of kinetic asymmetry and power strokes in an information ratchet

Chem, Год журнала: 2023, Номер 9(10), С. 2902 - 2917

Опубликована: Июнь 19, 2023

Biomolecular machines are driven by information ratchet mechanisms, where kinetic asymmetry in the machine's chemomechanical cycle of fuel-to-waste catalysis induces net directional dynamics. A large-scale energetically downhill conformational change, termed a "power stroke," has often been erroneously implicated as mechanistic driving feature such machines. We investigated roles and power strokes series rotaxane-based ratchets found that alone determines directionality all use same amount fuel to reach normalized steady state. However, can nonetheless influence performance, how fast state is reached. Moreover, nonequilibrium thermodynamic analysis revealed alter form (information [Shannon entropy] versus intercomponent binding energy) free energy stored ratchets. These findings have implications for both understanding biological design principles artificial (supra)molecular

Язык: Английский

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Photoresponsive Rotaxane-Branched Dendrimers: From Nanoscale Dimension Modulation to Macroscopic Soft Actuators

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(26), С. 14498 - 14509

Опубликована: Июнь 16, 2023

Aiming at the construction of novel soft actuators through amplified motions molecular machines nanoscale, design and synthesis a new family photoresponsive rotaxane-branched dendrimers an efficient controllable divergent approach was successfully realized for first time. In third-generation dendrimers, up to 21 azobenzene-based rotaxane units located each branch, thus making them successful light-control integrated artificial machines. Notably, upon alternative irradiation with UV visible light, photoisomerization azobenzene stoppers leads collective precisely arranged units, resulting in reversible dimension modulation integrating solution. Moreover, macroscopic were further constructed based on these which revealed fast shape transformation behaviors actuating speed 21.2 ± 0.2° s-1 ultraviolet irradiation. More importantly, resultant could produce mechanical work light control that has been employed weight-lifting cargo transporting, laying foundation toward smart materials can perform programmed events.

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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Kinetic Barrier Diagrams to Visualize and Engineer Molecular Nonequilibrium Systems

Small, Год журнала: 2023, Номер 19(14)

Опубликована: Янв. 26, 2023

Molecular nonequilibrium systems hold great promises for the nanotechnology of future. Yet, their development is slowed by absence an informative representation. Indeed, while potential energy surfaces comprise in principle all information, they hide dynamic interplay multiple reaction pathways underlying systems, i.e., degree kinetic asymmetry. To offer insightful visual representation asymmetry, we extended approach pertaining to catalytic networks, span model, focusing on system dynamics - rather than thermodynamics. Our encompasses both chemically and photochemically driven ranging from unimolecular motors simple self-assembly schemes. The obtained diagrams give immediate access information needed guide experiments, such as states' population, rate machine operation, maximum work output, effects design changes. proposed barrier a unifying graphical tool disparate phenomena.

Язык: Английский

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Photoactivated Artificial Molecular Motors

JACS Au, Год журнала: 2023, Номер 3(5), С. 1301 - 1313

Опубликована: Май 8, 2023

Accurate control of long-range motion at the molecular scale holds great potential for development ground-breaking applications in energy storage and bionanotechnology. The past decade has seen tremendous this area, with a focus on directional operation away from thermal equilibrium, giving rise to tailored man-made motors. As light is highly tunable, controllable, clean, renewable source energy, photochemical processes are appealing activate Nonetheless, successful motors fueled by challenging task, which requires judicious coupling photoinduced reactions. In paper, we key aspects light-driven artificial aid recent examples. A critical assessment criteria design, operation, technological such systems provided, along perspective view future advances exciting research area.

Язык: Английский

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A molecular anion pump

Science, Год журнала: 2024, Номер 385(6708), С. 544 - 549

Опубликована: Авг. 1, 2024

Pumping ions against a concentration gradient through protein-based transporters is cornerstone of numerous biological processes. Mimicking this function by using artificial receptors remains daunting challenge, mainly because the difficulties in balancing between requirement for high binding affinities and precise on-demand ion capture release properties. We report trimeric hydrazone photoswitch-based receptor that converts light energy into work actively transporting chloride anion dichloromethane liquid membrane, functioning as molecular pump. The system manifests ease synthesis, bistability, excellent photoswitching properties, superb ON-OFF properties (difference up to six orders magnitude).

Язык: Английский

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