Kinetic Asymmetry and Directionality of Nonequilibrium Molecular Systems

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(9)

Published: Jan. 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.

Language: Английский

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Transducing chemical energy through catalysis by an artificial molecular motor

Nature, Journal Year: 2025, Volume and Issue: 637(8046), P. 594 - 600

Published: Jan. 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.

Language: Английский

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Dynamic covalent synthesis

Chemical Science, Journal Year: 2023, Volume and Issue: 15(3), P. 879 - 895

Published: Dec. 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,

Language: Английский

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Endergonic synthesis driven by chemical fuelling

Nature Synthesis, Journal Year: 2024, Volume and Issue: 3(6), P. 707 - 714

Published: March 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.

Language: Английский

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Dynamic Promotion of the Oxygen Evolution Reaction via Programmable Metal Oxides

ACS Energy Letters, Journal Year: 2024, Volume and Issue: 9(5), P. 2013 - 2023

Published: April 8, 2024

Hydrogen gas is a promising renewable energy storage medium when produced via water electrolysis, but this process limited by the sluggish kinetics of anodic oxygen evolution reaction (OER). Herein, we used microkinetic model to investigate promoting OER using programmable oxide catalysts (i.e., forced catalyst dynamics). We found that could increase current density at fixed overpotential (100–600× over static rates) or reduce required reach 10 mA cm–2 (45–140% reduction vs static). In our kinetic parametrization, key parameters controlling quality catalytic ratchet were O*-to-OOH* and O*-to-OH* activation barriers. Our findings indicate may be viable strategy for accelerating enabling lower-overpotential operation, more accurate parametrization precise predictions performance, quality, resulting efficiency.

Language: Английский

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Photoswitchable Imines Drive Dynamic Covalent Systems to Nonequilibrium Steady States

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(30), P. 20720 - 20727

Published: July 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

Language: Английский

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Formylation boosts the performance of light-driven overcrowded alkene-derived rotary molecular motors

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(8), P. 1330 - 1338

Published: April 26, 2024

Language: Английский

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Structural Influence of the Chemical Fueling System on a Catalysis-Driven Rotary Molecular Motor

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 27, 2025

Continuous directionally biased 360° rotation about a covalent single bond was recently realized in the form of chemically fueled 1-phenylpyrrole 2,2′-dicarboxylic acid rotary molecular motor. However, original fueling system and reaction conditions resulted motor directionality only ∼3:1 (i.e., on average backward for every three forward rotations), along with catalytic efficiency operation 97% fuel 14%. Here, we report efficacy series chiral carbodiimide fuels hydrolysis promoters (pyridine pyridine N-oxide derivatives) driving improved directional this motor-molecule. We outline complete network operation, composed directional, futile, slip cycles. Using derivatives where final conformational step is either very slow or completely blocked, phenylpyrrole diacid becomes enantiomerically enriched, allowing kinetic gating individual steps cycle to be measured. The that produces highest gives 13% enantiomeric excess (e.e.) anhydride-forming kinetically gated step, while most effective promoter generates 90% e.e. step. Combining best-performing into results 92% e.e.. Under dilute chemostated regime (to avoid N-acyl urea formation at high concentrations promoters), continuously rotates ∼24:1 24 rotations) >99% 51%.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(7), P. 4467 - 4472

Published: Feb. 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.

Language: Английский

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A Minimalistic Covalent Bond‐Forming Chemical Reaction Cycle that Consumes Adenosine Diphosphate

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(22)

Published: March 27, 2024

Abstract The development of synthetic active matter requires the ability to design materials capable harnessing energy from a source carry out work. Nature achieves this using chemical reaction cycles in which released an exergonic is used drive biochemical processes. Although many chemically fuelled that control transient responses, such as self‐assembly, have been reported, generally high complexity reported systems hampers full understanding how available actually exploited by these systems. This lack limiting factor matter. Here, we report minimalistic responsive cycle adenosine diphosphate (ADP) triggers formation catalyst for its own hydrolysis. establishes interdependence between concentrations network components resulting catalyst. sufficiently simple all kinetic and thermodynamic parameters governing behaviour can be characterised, allowing models built simulate progress reactions within network. While current does not enable ADP‐hydrolysis populate non‐equilibrium composition, provide insight into way dissipates energy. Furthermore, essential principles are revealed constructing driven systems, composition away equilibrium through consumption

Language: Английский

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