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

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Фев. 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%.

Язык: Английский

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Precise Assembly/Disassembly of Homo-Type and Hetero-Type Macrocycles with Photoresponsive and Non-Photoresponsive Dynamic Covalent Bonds

Organic & Biomolecular Chemistry, Год журнала: 2025, Номер 23(10), С. 2498 - 2509

Опубликована: Янв. 1, 2025

Dynamic covalent macrocycles offer the advantage of tunable ring-opening/ring-closure and structural transformation, but their control with precision remains a daunting task due to labile nature reversible bonds. Herein we demonstrate precise formation/scission varied sizes by contrasting reactivity, stability, degradability light-active light-inactive dynamic The incorporation photoswitchable non-photoresponsive aldehyde sites into one single dialdehyde component afforded creation [1 + 1] type primary diamines suitable lengths. manipulation light acid/base stimuli allowed on-demand breaking/remaking macrocycles, achieving interconversion between macrocyclic linear skeletons. Moreover, combination dialdehyde, diamines, secondary enabled construction hetero-type [2 1 1'] via enhanced discrimination hierarchical assembly. Light-induced kinetic locking/unlocking bonds further macrocycle-to-macrocycle conversion when needed. Through leveraging controllable connection/disconnection, switchable formation/disintegration mechanically interlocked catenanes was accomplished. results described showcase potential photoinduced chemistry for preparing complex architectures should set stage molecular recognition, assemblies, synthetic motors, responsive materials.

Язык: Английский

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The Selective and Sensitive Fluorogenic Detection of Hydrogen Gas Using an Azomethine-H Dye

ACS Sensors, Год журнала: 2025, Номер unknown

Опубликована: Март 2, 2025

Hydrogen (H2(g)) is a viable green fossil fuel alternative, as its combustion yields only water and energy. However, H2(g) highly flammable, explosive, lacks odor. These characteristics warrant sensitive specific detection methods for widespread use an alternative source. Recently, there has been growing interest in the development of sensors, particularly those that are easy to use, environmentally friendly, sensitive. Here, we show first example optical fluorogenic hydrogen sensing platform, which employs readily available dye azomethine-H (Az-H, 4-hydroxy-5-(2-hydroxy-benzylideneamino)-naphthalene-2,7-disulfonic acid) hydrogen-transferring compound [{Ir(Cp*)(Cl)}2(thbpym)](Cl)2 (IrCp*, (Cp* = C5Me5-, thbpym 4,4',6,6'-tetrahydroxy-2,2'-bipyrimidine)) engineer gas selectivity with high sensitivity at room temperature pressure. This system ∼47-fold fluorescence enhancement when exposed aqueous solution or ∼2.4-fold carboxymethyl cellulose (CMC) hydrogel matrix, estimated limit ∼0.5% no cross-reactivity observed potentially contaminating gases such nitrogen (N2(g)), oxygen (O2(g)), air.

Язык: Английский

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A Catalysis-Driven Dual Molecular Motor

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

We report on a head-to-tail dual molecular motor consisting of two (identical) units whose pyrrole-2-carboxylic rings are turned in contra-rotary (i.e., disrotatory) fashion about common phenyl-2,5-dicarboxylic acid stator. The motors directionally rotate via information ratchet mechanisms, which the hydration carbodiimide (fuel) to form urea (waste) is catalyzed through chemomechanical cycle unit, resulting directional rotation biaryl C–N bond. arrangement produces coaxial contra-rotation end groups while central phenyl ring axis remains dynamically unbiased. electron-rich nature stator contributes rotary catalysis by dual-motor (and therefore itself) being ∼7× faster than parent 1-phenylpyrrole-2,2-dicarboxylic single-motor when operated under identical conditions, and 90× using originally reported reaction conditions. Under batch-fueled operation all fuel present at start operation), rotates an initial rate 0.43 rotations per minute (rpm). Chemostating concentration syringe pump addition produced sustained repetitive 0.24 rpm for period 100 min. demonstration chemically fueled continuous time scale 2–4 min significantly advances chemistry mechanics artificial catalysis-driven machinery.

Язык: Английский

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Applications of Luminescent Cyclometalated Metal Complexes as Sensors and Switches

Synlett, Год журнала: 2025, Номер unknown

Опубликована: Март 19, 2025

Abstract Cyclometalated complexes, including those with pincer ligands and other chelating frameworks, such as porphyrin rings polyenes, have garnered significant attention due to their diverse applications in ion analyte detection across synthetic chemistry, environmental monitoring, medicine, electronics. These complexes exhibit fascinating chromic behaviors, mechanochromism, chemochromism, vapochromism, which are particularly useful sensing applications. Of particular interest photophysical properties, especially involving lanthanides, offer unique luminescent optical characteristics. Metals nickel (Ni), palladium (Pd), ruthenium (Ru), gold (Au), rhodium (Rh) been extensively studied order understand photochemical activity explore potential light-emitting devices, photo-induced electron transfer, technologies. Their vapochromic mechanochromic properties make them highly attractive for sensing, while photoluminescent capabilities enhance utility optoelectronic devices practical This review provides a comprehensive overview of applications, gas, cation, anion sensing. The discussion also highlights the need incorporate specific examples that demonstrate suitability these targeted tasks, further emphasizing promise advancing sensor device 1 Introduction 2 Strategies 3 Applications 4 Other Miscellaneous Examples 5 Drawbacks Limitations 6 Conclusion Perspectives 7 List Abbreviations Definitions

Язык: Английский

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All‐Visible‐Light Azobenzene Photoswitches for Controlling Dynamic C—N Bonds^†

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 16, 2025

Comprehensive Summary The visible light‐driven photoswitches are attracting widespread attention, but it is challenging to leverage their phototriggered structural changes regulate dynamic bonds, assemblies, and materials. Herein, we incorporated reversible covalent sites of aldehyde ring‐chain tautomers into all‐visible‐light azobenzenes toward a versatile platform for light‐controlled formation/exchange C—N bonds from secondary amines. movement equilibrium was attained via manipulating intramolecular multiple hydrogen bonding E / Z configurational isomers. Such regulation further enabled photocontrolled kinetics the formation exchange reactions cyclic hemiaminal ethers amines exhibiting kinetic rate reversal varied capability isomers in engaging azo attached carboxylate with ammonium salt accounts difference. Moreover, photoswitching performance different solutions readily regulated by reactivity control light associated mechanistic foundation add collection photoswitchable chemistry would lay subsequent biological material applications.

Язык: Английский

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

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(43), С. 29621 - 29629

Опубликована: Окт. 17, 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 cascade reactions in aqueous media remains challenging due need control multiple, sequential a single pot manage stability reactive intermediates. Herein, we developed abiotic cascades 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 undergo hydrolysis, bypassing transformations after thioester formation. Additionally, mixtures containing multiple substrates, achieved selective product following distinct pathway favors subsequent through changes self-assembly. By coupling with molecules varying time scales, reaction clocks lifetimes dynamics, facilitating precise temporal regulation.

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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Iminobispyrazole (IBP) Photoswitches: Two Pyrazole Rings Can Be Better Than One

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

We recently demonstrated that suitably functionalised aryliminopyrazoles can exhibit useful photoswitching properties. This study investigates the potential of iminobispyrazoles (IBPs). find regiochemistry IBPs strongly dictates their properties, most notably,

Язык: Английский

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Light, Switch, Action! The Influence of Geometrical Photoisomerization in an Adaptive Self-Assembled System

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(46), С. 31892 - 31900

Опубликована: Ноя. 5, 2024

The ubiquitous ability of natural dynamic nanostructures to adapt environmental changes is a highly desirable property for chemical systems, particularly in the development complex matter, molecular machines, and life-like materials. Designing such systems challenging due generation mixtures with responses that are difficult predict, characterize, diversify. Here, we navigate between self-assembled architectures using light by operating an intrinsic photoswitchable building block governs state system. When complementary units present, photoswitch determines predominant architecture, reversibly adapting cage macrocycles, including (otherwise inaccessible) higher-energy assemblies. Our study showcases this concept seven different transformations, offering unprecedented degree control, diversification, adaptation self-selecting units. These findings could enable applications on-demand dissipative macrocycles based on bonds. We also envision transient nanostructures, e.g., reticular polymeric materials, being explored fine-tuning nature unit.

Язык: Английский

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