Controlling the motion of molecular machines to influence higher-order structures is well-established in biological systems but remains a significant challenge for synthetic analogs. Herein, we aim to harness the mechanical switching of switchable molecular tweezers to modulate their self-assembly and produce stimuli-responsive organogels. We report a series of terpy(Pt-salphen) molecular tweezers functionalized with alkyl chains that act as low-molecular-weight gelators (LMWGs) in their open conformation. The resulting organogels were thoroughly characterized by SEM, cryo-TEM, SAXS, and rheology. The macroscopic transition from gel to solution was achieved by the cation-induced closing of the tweezers, which triggers their substantial structural reorganization. Reversible sol-gel transitions were achieved through the sequential addition of chemical stimuli or by a decomposable acid in a time-controlled operation. Such transient disassembly process regulated by a chemical fuel enables multiple gelation cycles with minimal waste while maintaining stable rheological properties. These results underscore the potential of switchable molecular tweezers in creating advanced stimuli-responsive materials.

Sluggish redox kinetics and dendrite growth perplex the fulfillment of efficient electrochemistry in lithium-sulfur (Li-S) batteries. The complicated sulfur phase transformation and sulfur/lithium diversity kinetics necessitate an all-inclusive approach in catalyst design. Herein, a compatible mediator with nanoscale-asymmetric-size configuration by integrating Co single atoms and defective CoTe (Co-CoTe@NHCF) is elaborately developed for regulating sulfur/lithium electrochemistry synchronously. Substantial electrochemistry and theoretical analyses reveal that CoTe exhibits higher catalytic activity in long-chain polysulfide transformation and LiS decomposition, while monodispersed Co sites are more effective in boosting sulfur reduction kinetics to regulate LiS deposition. Such cascade catalysis endows Co-CoTe@NHCF with the all-around service of "trapping-conversion-recuperation" for sulfur species during the whole redox reaction. Furthermore, it is demonstrated by in situ transmission electron microscopy that initially formed electronic-conductive Co and ionic-conductive LiTe provide sufficient lithiophilic sites to regulate homogeneous Li plating and stripping with markedly suppressed dendrite growth. Consequently, by coupling the Co-CoTe@NHCF interlayer and Li@Co-CoTe@NHCF anode, the constructed Li-S full batteries deliver superior cycling stability and rate performance, and the flexible pouch cell exhibits stable cycling performance at 0.3 C. The gained insights into the synergistic effect of asymmetric-size structures pave the way for the integrated catalyst design in advanced Li-S systems.

Oxygen vacancies (OVs) spatially confined on the surface of metal oxide semiconductors are advantageous for photocatalysis, in particular, for O-involved redox reactions. However, the thermal annealing process used to generate surface OVs often results in undesired bulk OVs within the metal oxides. Herein, a high pressure-assisted thermal annealing strategy has been developed for selectively confining desirable amounts of OVs on the surface of metal oxides, such as tungsten oxide (WO). Applying a pressure of 1.2 gigapascal (GPa) on WO induces significant lattice compression, which would strengthen the W-O bonds and increase the diffusion activation energy for the migration of the O migration. This pressure-induced compression effectively inhibits the formation of bulk OVs, resulting in a high density of surface-confined OVs on WO. These well-defined surface OVs significantly enhance the photocatalytic activation of O, facilitating HO production and aerobic oxidative coupling of amines. This strategy holds promise for the defect engineering of other metal oxides, enabling abundant surface OVs for a range of emerged applications.

New approaches to achieve facile and reversible dihydrogen activation are of importance for synthesis, catalysis, and hydrogen storage. Here we show that low-coordinate magnesium oxide complexes [{(nacnac)Mg}(μ-O)] , with nacnac = HC(RCNDip), Dip = 2,6-PrCH, R = Me (), Et (), Pr (), readily react with dihydrogen under mild conditions to afford mixed hydride-hydroxide complexes [{(nacnac)Mg}(μ-H)(μ-OH)] . Dehydrogenation of complexes is strongly dependent on remote ligand substitution and can be achieved by simple vacuum-degassing of (R = Pr) to regain . Donor addition to complexes also releases hydrogen and affords donor adducts of magnesium oxide complexes. Computational studies suggest that the hydrogen activation mechanism involves nucleophilic attack of an oxide lone pair at a weakly bound H···Mg complex in an S2-like manner that induces a heterolytic dihydrogen cleavage to yield an MgOH and an MgH unit. Alternative synthetic routes into complex from a magnesium hydride complex have been investigated and the ability of complexes or to act as catalysts for the hydrogenation of 1,1-diphenylethene (DPE) has been tested.

The broad temperature adaptability associated with the desolvation process remains a formidable challenge for organic electrolytes in rechargeable metal batteries, especially under low-temperature (LT) conditions. Although a traditional approach involves utilizing electrolytes with a high degree of anion participation in the solvation structure, known as weakly solvation electrolytes (WSEs), the solvation structure of these electrolytes is highly susceptible to temperature fluctuations, potentially undermining their LT performance. To address this limitation, we have devised an innovative electrolyte that harnesses the interplay between solvent molecules, effectively blending strong and weak solvents while incorporating anion participation in a solvation structure that remains mostly unchanged by temperature variations. Remarkably, the competitive coordination between the two solvent molecules introduces local disorder, which not only boosts ionic conductivity but also prevents salt precipitation and solidification. Therefore, this electrolyte has a conductivity of 3.12 mS cm at -40 °C. NaV(PO)||Na cells demonstrated a high reversible capacity of 95.9 mAh g at -40 °C, which is 87.6% of that at room temperature, as well as stable cycling for 3400 cycles with capacity retention of 98.2% at -20 °C and 5 C and 600 cycles with capacity retention of 96.1% at -40 °C and 1 C. This study provides a new perspective on designing LT electrolytes by regulating temperature-robust solvation structures.

Triplet-sensitization has been proven invaluable for creating photoswitches operated over a full visible-light spectrum. While designing efficient triplet-sensitizers is crucial for establishing visible-light photochromism, it remains an appealing yet challenging task. In this work, we propose a versatile strategy to fabricate triplet-sensitizers with intermolecular charge-transfer complexes (CTCs). Through fine-tuning interactions between various donor and acceptor units, a series of CTC sensitizers were prepared with intensified visible-light absorption and a distinctive narrow Δ feature. By virtue of this, a bidirectional visible-light photochromism (475 nm/605 nm) was achieved via integrating CTC sensitizers with classic diarylethene (DAE) photoswitches in various substrates upon triplet photoreaction pathways. Proof-of-concept applications, such as photoresponsive printing and mechanic-facilitated inkpad, were subsequently presented. The flexible accessibility and tunability of CTC sensitizers facilitate both generalized and customized production of photoresponsive systems that operate within the visible-light region.

An original approach to characterize electrochemical interfaces at the atomic level, a challenging topic toward the understanding of electrochemical reactivity, is reported. We employed surface resonant X-ray diffraction experiments combined with their simulation using first-principle density functional theory calculations and were thus able to determine the molecular and electronic structures of the partially ionic layer facing the electrode surface, as well as the charge distribution in the surface metal layers. Pt(111) in an acidic medium at an applied potential excluding specific adsorption was studied. The presence of a positively charged counter layer composed of 1.60 water and 0.15 hydronium molecules per platinum surface unit cell at 2.8 Å from the oppositely charged Pt(111) surface was found. Our results give a unique insight into the water-metal interaction at the electrochemical interfaces.

The emergence of spinon quasiparticles, which carry spin but lack charge, is a hallmark of collective quantum phenomena in low-dimensional quantum spin systems. While the existence of spinons has been demonstrated through scattering spectroscopy in ensemble samples, real-space imaging of these quasiparticles within individual spin chains has remained elusive. In this study, we construct individual Heisenberg antiferromagnetic spin-1/2 chains using open-shell [2]triangulene molecules as building blocks. Each [2]triangulene unit, owing to its sublattice imbalance, hosts a net spin-1/2 in accordance with Lieb's theorem, and these spins are antiferromagnetically coupled within covalent chains with a coupling strength of J = 45 meV. Through scanning tunneling microscopy and spectroscopy, we probe the spin states, excitation gaps, and their spatial excitation weights within covalent spin chains of varying lengths with atomic precision. Our investigation reveals that the excitation gap decreases as the chain length increases, extrapolating to zero for long chains, consistent with Haldane's gapless prediction. Moreover, inelastic tunneling spectroscopy reveals an -shaped energy dispersion characteristic of confined spinon quasiparticles in a one-dimensional quantum box. These findings establish a promising strategy for exploring the unique properties of excitation quasiparticles and their broad implications for quantum information.

Samarium diiodide (SmI) exhibits high selectivity for NR catalyzed by molybdenum complexes; however, it has so far been employed only as a stoichiometric reagent (0.3 equiv of NH per Sm) combined with coordinating proton sources (e.g., HO, ROH). The latter inhibit catalytic turnover of Sm owing to buildup of stable hydroxide/alkoxide sinks. Here, we report a tandem Sm/Mo-catalyzed NR system that achieves the lowest overpotential and highest Faradaic efficiency (82%) reported to date for nonaqueous NR at ambient pressure. Up to 8.4 equiv of NH is produced per Sm, representing a 25-fold increase over NR with stoichiometric SmI. A noncoordinating proton source enables electrochemical SmI/SmI cycling at the applied potential of -1.45 V vs Fc.

Nitrenes (R-N) have been subject to a large body of experimental and theoretical studies. The fundamental reactivity of this important class of transient intermediates has been attributed to their electronic structures, particularly the accessibility of triplet vs singlet states. In contrast, electronic structure trends along the heavier pnictinidene analogues (R-Pn; Pn = P-Bi) are much less systematically explored. We here report the synthesis of a series of metallodipnictenes, {M-Pn═Pn-M} (M = Pd, Pt; Pn = P, As, Sb, Bi) and the characterization of the transient metallopnictinidene intermediates, {M-Pn} for Pn = P, As, Sb. Structural, spectroscopic, and computational analysis revealed spin triplet ground states for the metallopnictinidenes with characteristic electronic structure trends along the series. In comparison to the nitrene, the heavier pnictinidenes exhibit lower-lying ground state SOMOs and singlet excited states, thus suggesting increased electrophilic reactivity. Furthermore, the splitting of the triplet magnetic microstates is beyond the phosphinidenes {M-P} dominated by heavy pnictogen atom induced spin-orbit coupling.

Due to their strong aromaticity and difficulties in chemo-, regio-, and enantioselectivity control, asymmetric hydrogenation of naphthol derivatives to 1,2,3,4-tetrahydronaphthols has remained a long-standing challenge. Herein, we report the first example of homogeneous asymmetric hydrogenation of naphthol derivatives catalyzed by tethered rhodium-diamine catalysts, affording a wide array of optically pure 1,2,3,4-tetrahydronaphthols in high yields with excellent regio-, chemo-, and enantioselectivities (up to 98% yield and >99% ee). Mechanistic studies with experimental and computational approaches reveal that fluorinated solvent 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) plays vital roles in the control of reactivity and selectivity, and 1-naphthol is reduced via a cascade reaction pathway, including dearomative tautomerization, 1,4-hydride addition, and 1,2-hydride addition in sequence. A novel synergistic activation mode was proposed in which HFIP assists a synergistic activation of both the hydrogen molecule and naphthol in the presence of a base, and the in situ-generated fleeting keto tautomer is immediately trapped and reduced by the Rh(III)-H species before it escapes from the solvent cage. This protocol provides a straightforward and practical pathway for the synthesis of key intermediates for several chiral drugs. Particularly, optically pure Nadolol, a drug for the treatment of hypertension, angina pectoris, congestive heart failure, and certain arrhythmias, is enantioselectively synthesized for the first time.

Chain-end reactivation of polymethacrylates generated by reversible-deactivation radical polymerization (RDRP) has emerged as a powerful tool for triggering depolymerization at significantly milder temperatures than those traditionally employed. In this study, we demonstrate how the facile depolymerization of poly(butyl methacrylate) (PBMA) can be leveraged to selectively skew the molecular weight distribution (MWD) and predictably alter the viscoelastic properties of blended PBMA mixtures. By mixing polymers with thermally active chain ends with polymers of different molecular weights and inactive chain ends, the MWD of the blends can be skewed to be high or low by selective depolymerization. This approach leads to the counterintuitive principle of the "destructive strengthening" of a material. Finally, we demonstrate, as a proof of concept, the encryption of information within polymer mixtures by linking Morse code with the MWDs before and after selective depolymerization, allowing for the encoding of data within blends of synthetic macromolecules.

Carbon monoxide (CO) gas therapy, as an emerging therapeutic strategy, is promising in tumor treatment. However, the development of a red or near-infrared light-driven efficient CO release strategy is still challenging due to the limited physicochemical characteristics of the photoactivated carbon monoxide-releasing molecules (photoCORMs). Here, we discovered a novel photorelease CO mechanism that involved dual pathways of CO release via photosensitization. Specifically, the photosensitizer Chlorin e6 (Ce6) sensitized oxygen to produce singlet oxygen (O) and oxidized photoCORM Mn(CO) to release CO in an air-saturated solvent under red light (655 nm, 50 mW/cm) irradiation. Furthermore, Ce6 and Mn(CO) could undergo multistep photochemical reactions to release CO, as well as the degradation of the photosensitizer Ce6 in an oxygen-depleted solution. As a proof of concept, we demonstrated the feasibility and tumor inhibition of this CO release strategy both and . These results provide a robust platform for the development of new approaches to CO-mediated modulation of signaling pathways and further facilitate the practical use of gas therapeutic methods in tumor therapy .

Phase-separated coacervates can enhance reaction kinetics and guide multilevel self-assembly, mimicking early cellular evolution. In this work, we introduce "reactive" complex coacervates that undergo chemically triggered self-immolative transformations, directing the self-assembly of the reaction products within their matrix. These self-assemblies then evolve to show life-like properties such as budding and membrane formation. We find that the coacervate composition critically influences reaction rates and product distribution and guides the hierarchical self-assembly. This work showcases "reactive" coacervates as a versatile platform to influence reaction and self-assembly pathways for controlled supramolecular synthesis and hierarchical self-organization in confined spaces.

Misregulation of protein-protein interactions (PPIs) underlies many diseases; hence, molecules that stabilize PPIs, known as molecular glues, are promising drug candidates. Identification of novel molecular glues is highly challenging among others because classical biochemical assays in dilute aqueous conditions have limitations for evaluating weak PPIs and their stabilization by molecular glues. This hampers the systematic discovery and evaluation of molecular glues. Here, we present a synthetic condensate platform for the study of PPIs and molecular glues in a crowded macromolecular environment that more closely resembles the dense cellular milieu. With this platform, weak PPIs can be enhanced by sequestration. The condensates, based on amylose derivatives, recruit the hub protein 14-3-3 via affinity-based uptake, which results in high local protein concentrations ideal for the efficient screening of molecular glues. Clients of 14-3-3 are sequestered in the condensates based on their enhanced affinity upon treatment with molecular glues. Fine control over the condensate environment is illustrated by modulating the reactivity of dynamic covalent molecular glues by the adjustment of pH and the redox environment. General applicability of the system for screening of molecular glues is highlighted by using the nuclear receptor PPARγ, which recruits coregulators via an allosteric PPI stabilization mechanism. The condensate environment thus provides a unique dense molecular environment to enhance weak PPIs and enable subsequent evaluation of small-molecule stabilization in a molecular setting chemically en route to the cellular interior.

Recently, cobalt-based oxides have received considerable attention as an alternative to expensive and scarce iridium for catalyzing the oxygen evolution reaction (OER) under acidic conditions. Although the reported materials demonstrate promising durability, they are not entirely intact, calling for fundamental research efforts to understand the processes governing the degradation of such catalysts. To this end, this work studies the dissolution mechanism of a model CoO porous catalyst under different electrochemical conditions using online inductively coupled plasma mass spectrometry (online ICP-MS), identical location scanning transmission electron microscopy (IL-STEM), and differential electrochemical mass spectrometry (DEMS). Despite the high thermodynamics tendency reflected in the Pourbaix diagram, it is shown that the cobalt dissolution kinetics is sluggish and can be lowered further by modifying the electrochemical protocol. For the latter, identified in this study, several (electro)chemical reaction pathways that lead to the dissolution of CoO must be considered. Hence, this work uncovers the transient character of cobalt dissolution and provides valuable insights that can help to understand the promising stability of cobalt-based materials in already published works and facilitate the knowledge-driven design of novel, stable, abundant catalysts toward the OER in an acidic environment.

Electrocatalytic dehalogenative deuteration is a sustainable method for precise deuteration, whereas its Faradaic efficiency (FE) is limited by a high overpotential and severe D evolution reaction (DER). Here, Cu site-adjusted adsorption and crown ether-reconfigured interfacial DO are reported to cooperatively increase the FE of dehalogenative deuteration up to 84% at -100 mA cm. Cu sites strengthen the adsorption of aryl iodides, promoting interfacial mass transfer and thus accelerating the kinetics toward dehalogenative deuteration. The crown ethers disrupt the hydration effect of K·DO and reconstruct the hydrogen bond with the interfacial DO, lowering the content K·DO of the electric double layer and hindering the interaction between DO and the cathode, thus inhibiting the kinetics of the competitive DER. A linear relationship between the matched sizes of crown ethers and alkali metal cations is demonstrated for universally increasing FEs. This method is also suitable for the deuteration of various halides with high easily reducible functional group compatibility and improved FEs at -100 mA cm.

Transitions between chiral rotational locomotion modes occur in a variety of active individuals and populations, such as sidewinders, self-propelled chiral droplets, and dense bacterial suspensions. Despite recent progress in the study of active matter, general principles governing rotational chiral transition remain elusive. Here, we study, experimentally and theoretically, rotational locomotion and its chiral transition in a 2D polyacrylamide (PAAm)-based BZ gel driven by Belousov-Zhabotinsky reaction-diffusion waves. Analysis reveals that the phase difference (Δφ) between orthogonal components of kinematic quantities, such as chemomechanical force, displacement, and velocity, determines rotational chirality, i.e., chiral locomotion transition occurs when Δφ changes sign. This criterion is illustrated with a kinematic equation, which can be applied to biological and physical systems, including super-rotational/superhelical locomotion reported recently during swimming and sperm navigation. This work has potential applications for the design of functional materials and intelligent robots.

The local environment of the active site, such as the confinement of hydronium ions within zeolite pores, significantly influences catalytic turnover, similar to enzyme functionality. This study explores these effects in the hydrolysis of guaiacols─lignin-derived compounds─over zeolites in water. In addition to the interesting catechol products, this reaction is advantageous for study due to its bimolecular hydrolysis pathway, which involves a single energy barrier and no intermediates, simplifying kinetic studies and result interpretation. As in alcohol dehydration, hydronium ions show enhanced activity in ether hydrolysis due to undercoordination and increased electrophilicity when confined within zeolite pores, compared to bulk water. In addition, a volcano-shaped relationship between hydronium ion activity and Brønsted acid density was observed. However, unlike alcohol dehydration, this activity distribution cannot be attributed to variations in ionic strength within the pores, as the rate-determining step in the hydrolysis of guaiacols involves the attack of a neutral water molecule, unaffected by ionic strength. Instead, a detailed transition state analysis revealed a significant thermodynamic energy compensation effect, driven by the spatial organization of the transition state. This organization is influenced by the available reaction space, the interaction between the reacting species and the zeolite environment, leading to the volcano-shaped dependence. This phenomenon also explains the unusual reactivity order of the 4-R-guaiacol derivatives (R = H, Me, Et, Pr) with zeolite catalysis, extending beyond the traditional steric and electronic effects to provide a deeper understanding of reactant reactivity. The work concludes that the critical spatial parameters for fast ether hydrolysis─resulting in the highest hydronium activity─are determined by a combination of zeolite properties (topology and acid density) and reactant size.

Epoxides are versatile chemical intermediates that are used in the manufacture of diversified industrial products. For decades, thermochemical conversion has long been employed as the primary synthetic route. However, it has several drawbacks, such as harsh and explosive operating conditions, as well as a significant greenhouse gas emissions problem. In this study, we propose an alternative electrocatalytic epoxidation reaction, using [Co(TAML)] (TAML = tetraamido macrocyclic ligand) as a molecular catalyst. Under ambient conditions, the catalyst selectively epoxidized olefin substrates using water as the oxygen atom source, affording an efficient catalytic epoxidation of olefins with a broad substrate scope. Notably, [Co(TAML)] achieved >60% Faradaic efficiency (FE) with >90% selectivity for cyclohexene epoxidation, which other heterogeneous electrocatalysts have never attained. Electrokinetic studies shed further light on the detailed mechanism of olefin epoxidation, which involved a rate-limiting proton-coupled electron transfer process, forming reactive cobalt oxygen active species embedded in 2eoxidized TAML. Operando voltammetry-electrospray ionization mass spectrometry (VESI-MS) and electron paramagnetic resonance (EPR) analyses were utilized to identify a cobalt oxygen active intermediate during an electrocatalytic epoxidation by [Co(TAML)]. Our findings offer a new possibility for sustainable chemical feedstock production using electrochemical methods.