Kinetic Trapping of an Out‐of‐Equilibrium Dynamic Library of Imines by Changing Solvent

Chemistry - A European Journal, Год журнала: 2024, Номер 30(37)

Опубликована: Апрель 8, 2024

A well-behaved dynamic library composed of two imines and corresponding amines was subjected to the action an activated carboxylic acid (ACA), whose decarboxylation is known be base promoted, in different solvents, namely CD

Язык: Английский

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Directionality Reversal and Shift of Rotational Axis in a Hemithioindigo Macrocyclic Molecular Motor

Опубликована: Апрель 23, 2024

Molecular motors are central driving units for nanomachinery and control of their directional motions is fundamental importance functions. Light-driven variants use an easy to provide, dose, waste free fuel with high energy content, which makes them particularly interesting many applications. Typically, light-driven molecular work via rotations around dedicated chemical bonds (e.g. double bonds) where directionality the rotation dictated by steric effects asymmetry in close vicinity axis. In this we show how unidirectional a virtual axis can be realized reprogramming motor. To end, classical motor restricted macrocyclization its intrinsic transformed into macrocyclic chain opposite direction. Further, solvent polarity changes allow toggle function machine between non-directional photoswitch. way new concept design delivered together elaborate over functions simple changes. The possibility sensing environmental correspondingly adjusting opens up next level responsiveness nanoscopic motors.

Язык: Английский

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Transducing chemical energy through catalysis by an artificial molecular motor

Опубликована: Май 24, 2024

Cells display a range of mechanical activities enabled by the cytoskeleton, viscoelastic hydrogel manipulated motor proteins powered through catalysis. This raises question how acceleration chemical reaction can enable energy released from that to be transduced, and thereby work done, molecular catalyst. Here we demonstrate molecular-level transduction force in form contraction re-expansion crosslinked polymer gel driven directional rotation embedded artificial catalysis-driven motors. Continuous 360° rotor about stator motor-molecules incorporated within polymeric framework gel, twists chains network around one another (either clockwise or anti-clockwise, depending on chirality fuelling system). progressively increases writhe tightens entanglements, causing macroscopic ~70% its original volume. The limit corresponds stall motor; point at which, despite catalysis continuing, untwisting exerted entwined strands balances conformation selection motor’s catalytic cycle. Subsequent addition opposite enantiomeric system powers contracted reverse direction, unwinding entanglements re-expand. Continued twisting new direction causes contract once again. experimental demonstration against load synthetic catalyst, mechanism catalyst kinetic asymmetry fuel-to-waste reaction, informs both debate surrounding generation biological motors design principles for nanotechnology.

Язык: Английский

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Physico-chemical principles of AC electrosynthesis: reversible reactions

Опубликована: Июль 26, 2024

Electrolysis integrates renewable energy into chemical manufacturing and is key towards sustainable chemistry. Controlling the waveform beyond direct current (DC) addresses long-standing obstacle of chemoselectivity, yet it also expands parameter set to optimise, creating a demand for theoretical predictions. Here, we report first analytical theory predicting chemoselectivity in alternating (AC) electrosynthesis. The mechanism selective reversal unwanted redox reaction during periods opposite polarity, reflected final outcome as time-averaged effect. In ideal scenario all reactions being reversible, square AC biases more overoxidation/overreduction, whereas sine exhibits However, realistic some quasi-reversible, may behave mostly like AC. These predictions are numerical agreement with model experiments employing acetophenone align qualitatively literature precedent. Collectively, this study provides proof growing trend that promotes changing overcome limitations challenging address by varying canonical electrochemical parameters.

Язык: Английский

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Abiotic Acyl Transfer Cascades Driven by Aminoacyl Phosphate Esters and Self-Assembly

Опубликована: Авг. 5, 2024

Biochemical acyl transfer cascades, such as those initiated by the adenylation of carboxylic acids, are central to various biological processes, including protein synthesis and fatty acid metabolism. Designing aqueous cascades outside biology remains challenging due need control multiple, sequential reactions in a single pot manage stability reactive intermediates. Herein, we developed abiotic using aminoacyl phosphate esters, synthetic counterparts adenylates, drive chemical self-assembly pot. We demonstrated that structural elements amino side chains (aromatic versus aliphatic) significantly influence reactivity half-lives ranging from hours days. This behavior, turn, affects number couplings can achieve network propensity activated intermediate structures. The constructed bifunctional peptide substrates featuring chain nucleophiles. Specifically, aromatic acids facilitate formation transient thioesters, which preorganized into spherical aggregates further couple chimeric assemblies composed esters thioesters. In contrast, aliphatic lack ability form structures, predominantly lead hydrolysis, bypassing elongation after thioester formation. Additionally, mixtures containing multiple substrates, achieved selective product following distinct pathway favors through self-assembly. By coupling molecules with varying timescales, reaction clocks lifetimes dynamics, thereby facilitating precise temporal regulation.

Язык: Английский

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