Bauer M, Pichl O, Scherz F
… +6 more, Pech M, Carle NO, Krewald V, Sarkar B, Domenianni LI, Vöhringer P
J Am Chem Soc
· 2026 Jun · PMID 42370857
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Ferrocene-based radicals and diradicals with ligand-centered spin density are highly promising building blocks for extended magnetic materials. In addition, the unpaired electrons may dress such systems with intriguing l...Ferrocene-based radicals and diradicals with ligand-centered spin density are highly promising building blocks for extended magnetic materials. In addition, the unpaired electrons may dress such systems with intriguing ligand-centered chemical reactivity that can be utilized for structural diversification of the functional material. Just like their inorganic analogues, metallonitridyls and metallonitrenes, nitrogen-centered organic radicals and diradicals, like iminyls and nitrenes, are particularly appealing spin centers because they offer an elegant entry into a wide spectrum of chemical reactivities ranging from remote CC-functionalization and radical relay to CH-amination and amidation. Here, we report on the photochemical generation of an exceptional metal-ligand ferrocene diradical from a photolabile diamagnetic azidoferrocene precursor. The diradical product has a triplet electronic ground state and contains the organic cyclopentadiene-iminyl neutral radical ligand (S = 1/2) that is ferromagnetically coupled to a low-spin (S = 1/2) iron(I) center. This unique species appears within 13 ps after optical excitation of the precursor and is formed with a primary quantum yield of 50%. Within less than 1 ps after impulsive electronic excitation in its metal-to-ligand charge-transfer region, the azidoferrocene finds itself in an excited quintet azide-ππ* state, which is electronically preconfigured to adiabatically release dinitrogen and to form a quintet iminyl intermediate. The latter then undergoes a rapid intersystem crossing to the triplet iminyl final product. The presence of the terminal iminyl moiety was verified unambiguously by conducting the optical excitation in the presence of an isonitrile quencher, thereby trapping the photochemical diradical product as a ferrocenyl carbodiimide.
Pradhan S, Meel AK, Pal S
… +4 more, Ghosh S, Banerjee A, Mogurampelly S, Narayanan TN
J Am Chem Soc
· 2026 Jun · PMID 42370832
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Electrolyte engineering strategies that exploit nonfluorinated solvents at low electrolyte concentrations are crucial for enabling next-generation high-performance and safer batteries, including zero-excess lithium metal...Electrolyte engineering strategies that exploit nonfluorinated solvents at low electrolyte concentrations are crucial for enabling next-generation high-performance and safer batteries, including zero-excess lithium metal batteries (ZELMBs). We demonstrate such a protocol using ether-based solvents, wherein the coordination of Li by distinct anions within the solvation shell enhances the Li transference number and stabilizes interfacial passivation. The tendency of solvents to form clusters facilitates Li desolvation prior to plating, enhancing ZELMB cycling performance to approximately 80%. At a comparatively low concentration (1.4 M) of salts in nonfluorinated solvents, the electrolyte stabilizes ZELMB performance with an average Coulombic efficiency of ∼98%. A cell employing an NMC811 cathode and a Cu current collector can sustain >90 cycles with >50% capacity retention. Spectroscopic and molecular dynamics analyses reveal cooperative solvent-anion clustering that drives the transition from solvent-dominated to mixed ion-solvent Li coordination, underpinning enhanced transport. This study establishes a pathway for designing low-cost, fluorine-free solvent-based electrolytes for metal batteries of extended cyclability.
Liu ZJ, Zhang Z, Cawthorn R
… +3 more, Sun M, Giebink NC, Nelson KA
J Am Chem Soc
· 2026 Jun · PMID 42370830
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Excitons serve as the primary energy carriers for many organic semiconductor devices and chemical systems; however, understanding how these bound electron-hole pairs dissociate into free carriers on an ultrafast time sca...Excitons serve as the primary energy carriers for many organic semiconductor devices and chemical systems; however, understanding how these bound electron-hole pairs dissociate into free carriers on an ultrafast time scale remains challenging. Here, we demonstrate a contact-free approach using intense, single-cycle terahertz (THz) pulses to promote the dissociation of excitons via a field-induced charge hopping process. Applying this method to a prototypical organic semiconductor, we observe a photocurrent enhancement exceeding 100% under THz excitation. Time-resolved measurements reveal that hot excitons (formed immediately after above-bandgap photoexcitation) are particularly susceptible to dissociation. These findings establish a nonequilibrium, field-driven route for engineering exciton dissociation in a wide range of optoelectronic materials, providing a broadly applicable strategy to enhance photovoltaic performance as well as potential electrophotocatalytic applications through strong-field light-matter interactions.
J Am Chem Soc
· 2026 Jun · PMID 42370788
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Intelligent responsive materials are important components for molecular machines and memory devices. However, the mechanism of guest-induced chirality inversion remains elusive because guest binding is typically too fast...Intelligent responsive materials are important components for molecular machines and memory devices. However, the mechanism of guest-induced chirality inversion remains elusive because guest binding is typically too fast to resolve the process. To address this challenge, it is necessary to develop a system in which chirality inversion and guest uptake occur on comparable, slow time scales. Here, we report a triple-helical closed-cage cobalt(III) metallocryptand incorporating three bridging 1,7-heptanediamine (hpda) ligands, which creates a closed-cage architecture that significantly slows guest uptake/release. X-ray crystallography revealed the formation of a (,) diastereomer with a right-handed triple-helical structure. In solution, a dynamic equilibrium between the (,) and (,) diastereomers was observed with slow interconversion ( = 20 min). Upon addition of CsCl, the / chirality was gradually inverted from a -abundant state to an -abundant state over several hours, associated with slow Cs uptake. The closed-cage design with bridging hpda ligands significantly slowed both Cs uptake and / interconversion, allowing the two processes to proceed on comparable, slow time scales. Kinetic analysis based on a four-species reversible model revealed that Cs is preferentially taken up in the less abundant form, whereas form does not directly bind Cs but instead contributes to uptake after → isomerization. The form binds Cs more strongly than the form, thus driving the → chirality inversion through this -form-mediated pathway. In contrast, addition of Cl shifted the equilibrium toward the more -favored mixture by interacting with Cl at the peripheral binding pocket, highlighting its opposite stereodynamic effect relative to Cs. These findings demonstrate that cage closure modulates both the timing and sequence of events during the pathway of guest-induced chirality inversion, and provide a kinetic platform for probing guest effects on stereodynamic equilibria. We also anticipate that the strategies used here can be applied to the rational design of other smart molecular architectures.
Jiang Z, Bancroft WF, Du CNA
… +2 more, Shieh M, Xian M
J Am Chem Soc
· 2026 Jun · PMID 42370674
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Protein -persulfidation is a key post-translational modification in redox signaling. In this process, hydropersulfides (RSSH) and hydrogen persulfide (HS) act as regulatory sulfane sulfur species, transferring their elec...Protein -persulfidation is a key post-translational modification in redox signaling. In this process, hydropersulfides (RSSH) and hydrogen persulfide (HS) act as regulatory sulfane sulfur species, transferring their electrophilic sulfane sulfur (S) atoms to protein thiols (P-SH) to form protein persulfides (P-SSH). Due to the high reactivity and instability of RSSH/HS, controllable donors are essential chemical tools for inducing protein -persulfidation. Existing donors are primarily disulfide-based; however, this structural feature leads to a major limitation, as disulfide-based donors are known to undergo unavoidable disulfide exchange reactions with cellular thiols (e.g., glutathione (GSH), cysteine (Cys)) and subsequently lose their ability to release the desired RSSH/HS. In this work, we proposed that thiosulfoxides [R-S(═S)-R'] could serve as equivalents of RSSH/HS for protein -persulfidation and that controlled thiosulfoxide formation is an alternative way for the design of RSSH/HS donors. To prove the hypothesis, we studied spontaneous [2,3]-sigmatropic allyl disulfide rearrangements with a variety of allyl disulfide substrates. We identified structural elements that promote the rearrangement to form thiosulfoxide adducts and demonstrated that the resulting transient thiosulfoxide intermediates were effective S transfer agents. Based on this discovery, we developed stable allyl disulfide reagents (such as ) that could be selectively activated by cellular thiols via the inevitable disulfide exchange, followed by a [2,3]-sigmatropic rearrangement cascade to induce protein -persulfidation. Our results present a conceptually new way to deliver reactive sulfane sulfur species in biological systems.
Luo N, Chen ZJ, Wu J
… +5 more, Zheng R, Zhang T, Peng J, Chen S, Cheng HM
J Am Chem Soc
· 2026 Jun · PMID 42370577
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Understanding how the electronic environment regulates catalyst reconstruction is essential for advancing biomass electro-oxidation. Here, we design a series of model catalysts by anchoring NiO species on two-dimensional...Understanding how the electronic environment regulates catalyst reconstruction is essential for advancing biomass electro-oxidation. Here, we design a series of model catalysts by anchoring NiO species on two-dimensional MS nanosheets (M = Sn, Ta, Mo, Ti) to probe how the electronic properties of substrates influence catalytic performance. Substrates with a lower carrier concentration were found to induce stronger interfacial charge transfer from NiO, generating electron-deficient Ni centers that readily reconstruct into an active NiOOH phase. Spectroscopic analyses reveal elongated Ni-O bonds and elevated Ni valence, consistent with enhanced oxidation propensity. Consequently, the NiO/SnS catalyst can be operated at an ampere-level current density at 1.45 V vs RHE, with 98.7% FDCA yield, 99% Faradaic efficiency, and robust cycling stability. Density functional theory calculations further show that interfacial charge redistribution lowers the adsorption barriers of HMF and *OH, accelerating the deprotonation step. This work offers insights into the rational design of high-performance biomass electro-oxidation catalysts.
Cowen XR, Georges T, Holmes JB
… +6 more, Bayram SE, Testino A, Torruella P, Hébert C, Scrivener KL, Emsley L
J Am Chem Soc
· 2026 Jun · PMID 42370422
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The early hydration of calcium silicate hydrate (C-S-H) plays a crucial role in the development of key mechanical properties in cement, yet an atomic-level description of this reaction remains elusive. Here, to understan...The early hydration of calcium silicate hydrate (C-S-H) plays a crucial role in the development of key mechanical properties in cement, yet an atomic-level description of this reaction remains elusive. Here, to understand the early stages of the hydration reaction, we introduce a method to quantify dilute silicate species as a function of reaction time using solid-state Si magic-angle spinning dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) spectroscopy. Samples are flash-frozen and separated by centrifugation, allowing for kinetic analysis of the supernatant and structural studies of the precipitate over time. With DNP-enhanced Si NMR, we can determine the concentrations of various silicate species throughout the reaction and track the growth of the silicate chains, which form the dreierketten backbone of C-S-H. In our low Ca/Si ratio system, we observe a vast majority of the supernatant silicate species to be monomers, with small amounts of dimers. The initially precipitated C-S-H, which has a mean chain length of 2.6 and is composed primarily of dimers, is shown to significantly differ from the C-S-H present after 3 h of hydration, which has an average length of 4.2.
Kakiuchi Y, Shapovalova S, Guda A
… +1 more, Copéret C
J Am Chem Soc
· 2026 Jun · PMID 42370420
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Transition metal-nitrosyl species holds prime importance in chemistry, yet describing their bonding remains a great challenge. Envisioning to develop a spectroscopic descriptor that addresses nitrosyl electronic structur...Transition metal-nitrosyl species holds prime importance in chemistry, yet describing their bonding remains a great challenge. Envisioning to develop a spectroscopic descriptor that addresses nitrosyl electronic structure, N solid-state NMR (ssNMR) spectroscopy, augmented by computational analysis, is herein applied to probe and disentangle the bonding in a family of low-valent Cr-nitrosyl complexes. Combined with complementary techniques (scXRD, IR, and X-ray absorption spectroscopy) pointing at a significant π-back-donation, N ssNMR-assisted orbital analysis highlights the formation of filled π(Cr-N) orbitals. Bonding analysis, anchored on spectroscopic data, reveals an increased Cr-N bond order reminiscent of a potential Cr-N multiple-bond character, which revisits the known analogy between nitrosyl and imido/nitrido ligands. Further analysis hints to a non-negligible influence of ancillary ligand, where strong σ-donor enhances Cr-N π-bonding. The sensitive response to the nitrosyl bonding and the ease to record N ssNMR signature and its link to the underlying electronic structures makes it privilege descriptor to understand metal-nitrosyl bonding at molecular (orbital) level.
Escalera-López D, Anastacio R, Gomez Rodellar C
… +3 more, Frandsen W, Oener SZ, Roldan Cuenya B
J Am Chem Soc
· 2026 Jun · PMID 42370418
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Electrodeposition is a key technology for the fabrication of semiconductor interconnects, corrosion protection, decorative coatings, and even for chemical energy storage in batteries. Empirically discovered additives are...Electrodeposition is a key technology for the fabrication of semiconductor interconnects, corrosion protection, decorative coatings, and even for chemical energy storage in batteries. Empirically discovered additives are regularly implemented in electroplating baths, but their impact on the electrodeposition mechanism, which involves the desolvation of metal ions across the electric-field-dependent double layer, has remained poorly understood. Herein, we perform overpotential-dependent Arrhenius analysis on Zn electrodeposition from strongly solvated zincate ([Zn(OH)])-containing alkaline electrolytes in the absence and presence of the cationic polyquaternium-2 (PQ-2) electrolyte additive. We hypothesized that the water-soluble and positively charged PQ-2 can modulate the double-layer electrostatics, leading to distinct changes in the Arrhenius activation parameters. Without PQ-2, we observe that electrodeposition competes with hydrogen evolution, which is reflected in an extended region where an increasing (apparent) activation energy is overcompensated by an increasing Arrhenius prefactor. In contrast, when we add the positively charged PQ-2, we observe that the compensation region is suppressed and the Zn deposition kinetics proceed via efficient Butler-Volmer-type kinetics. The latter might arise due to charge inversion and a closer approach of the negatively charged zincate to the electrode surface that allows for electron transfer. Quartz crystal microbalance and electron microscopy support that the Butler-Volmer kinetics arise from a surface-controlled mechanism, which is linked to distinct morphological changes on the surface. These results are important to understand how the interfacial microenvironment can tune the activity and selectivity and how electrochemical kinetics can switch between solvation and surface-controlled regimes.
Qian S, Wang T, Wang Y
… +7 more, Chang J, Cheng J, Nie K, Su D, Yan B, Cheng Y, Yan N
J Am Chem Soc
· 2026 Jun · PMID 42366937
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Harnessing lattice nitrogen for the direct conversion of dinitrogen (N) into organonitrogen compounds remains a grand challenge in heterogeneous catalysis. Herein, we report a nitride-mediated looping strategy for alcoho...Harnessing lattice nitrogen for the direct conversion of dinitrogen (N) into organonitrogen compounds remains a grand challenge in heterogeneous catalysis. Herein, we report a nitride-mediated looping strategy for alcohol amination, enabled by a Co-Mo bimetallic nitride operating as a rechargeable nitrogen carrier. The nitrogen carrier interacts with alcohol substrates to generate amines, followed by regeneration in a N/H atmosphere to achieve a rechargeable cycle. Using 1-octanol as the substrate to produce trioctylamine (TOA), this process enables stable amine production of 42.2 μmolTOA·g at 250 °C and 10 bar H for 5 cycles. Electron microscopy and spectroscopy studies demonstrate that lattice N release occurs within nanoscale regions over the Co-Mo nitride surface, while the bulk structure remains stable. This unique quasi-topological flexible structural transition concurrently attains reaction and regeneration capabilities, facilitating easy turnover of -related species. Kinetic analysis indicates that the nucleophilic attack of lattice N on aldehyde intermediates constitutes the rate-determining step. The TOA exhibits a product-assisted promotion effect, modulating the electronic structure of the nitride surface to promote the lattice N reactivity and desorption of the amine product. This work provides an approach for the N activation and conversion to valuable organic -containing compounds via the Co-Mo bimetallic nitride.
Hou B, Liu J, Wang X
… +10 more, Formalik F, Ye ZM, Xie H, Kong XJ, Su S, Tang X, Magdalenski JS, Kirlikovali KO, Snurr RQ, Farha OK
J Am Chem Soc
· 2026 Jun · PMID 42366918
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Achieving high crystallinity and controlled framework flexibility in covalent organic frameworks (COFs) remains a significant challenge for dynamic gas adsorption. Here we report a three-dimensional COF obtained through...Achieving high crystallinity and controlled framework flexibility in covalent organic frameworks (COFs) remains a significant challenge for dynamic gas adsorption. Here we report a three-dimensional COF obtained through a single-crystal-to-single-crystal imine-to-amine linkage transformation that exhibits flexible yet robust adsorption behavior. A rigid imine-linked single-crystal COF () was converted into its amine-linked analogue () by postsynthetic Leuckart-Wallach reduction with formic acid, while preserving single crystallinity. Despite their identical topologies, and exhibit distinct structural responses during guest adsorption-desorption processes: retains its framework rigidity, whereas polar molecules (e.g., SO, HO, MeOH) induce pore-opening behavior in . PXRD indicates that undergoes a reversible transformation from a guest-stabilized crystalline phase to a distorted phase with reduced long-range order upon guest removal. Notably, achieves an exceptionally high SO uptake of 10.4 mmol g at 298 K and 1 bar, representing one of the highest values reported for COFs under ambient conditions, despite exhibiting negligible N uptake at 77 K. Experimental and computational analyses reveal that activation induces a folded state in retaining guest-accessible volume prior to further pore expansion, with framework compression accommodated through cooperative folding and torsional distortion. In addition, the secondary amine linkages reduce the energetic penalty for framework deformation, allowing strong host-guest interactions with SO to drive pore adaptation while preserving structural integrity during the reversible disorder-order-disorder transformation observed in SO sorption. These findings establish linkage-controlled structural adaptation as a design strategy for dynamic gas adsorption in chemically aggressive environments.
Rukes V, Norkute E, Barnikol G
… +3 more, Duan J, Gao J, Cao C
J Am Chem Soc
· 2026 Jun · PMID 42366868
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Proteins play essential roles in cellular processes and are involved in numerous diseases, driving the need for efficient proteoform identification. Recent advances have brought nanopore-based protein fingerprinting with...Proteins play essential roles in cellular processes and are involved in numerous diseases, driving the need for efficient proteoform identification. Recent advances have brought nanopore-based protein fingerprinting within reach, potentially expanding the proteomics toolkit in the near future. Among emerging strategies, label-free, full-length analysis via free translocation is the most promising approach for detecting low-abundance proteoforms. While free translocation is typically accompanied by low temporal resolution, we demonstrate here that such measurements can enable reliable identification even for natural proteins with high sequence similarity. Combining low pH and guanidinium chloride, we generate a strong electroosmotic flow that enables efficient capture and translocation of unlabeled proteins with an aerolysin nanopore. Using machine learning classifiers, we achieve 80% accuracy in distinguishing seven related proteins, based on distinct and directional fingerprints with high reproducibility. Differences in fingerprints partially reflect the distribution of volume and charges in the protein sequences and may contain additional contributions from the translocation dynamics. Our findings position free-translocation measurements of unfolded proteins as a promising approach to fingerprinting without the need for chemical conjugations or enzymatic digestions. With further development, fingerprint-predictions could allow to infer protein sequence information from single-molecule data, offering a powerful tool for proteomics.
Li Y, Liu Y, Wang D
… +3 more, Zhao M, Zhang B, Wang Z
J Am Chem Soc
· 2026 Jun · PMID 42366839
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Electrochemical synthesis provides a promising strategy in the synthetic industry because of its benign conditions, strong economic viability, and environmental friendliness, but its application in the synthesis of COFs...Electrochemical synthesis provides a promising strategy in the synthetic industry because of its benign conditions, strong economic viability, and environmental friendliness, but its application in the synthesis of COFs is still challenging. Here, we report an electrochemical-assisted synthesis strategy to prepare imine-linked COFs directly from inexpensive aromatic multialcohols via in situ formation of aldehyde monomers followed by a Schiff base reaction with amine monomers in one pot. Unlike conventional strategies, this synthetic methodology avoids the time-consuming presynthesis and purification steps of organic monomers, enabling the economical and efficient fabrication of imine-linked COFs. Three aromatic multialdehydes and 11 different COFs are successfully synthesized, and compared with COFs made via other reported procedures, the obtained COFs have higher crystallinity and porosity. Furthermore, highly efficient electrochemical oxidation of multialcohols into multialdehydes using KBr/ABNO as a double mediator was first demonstrated, resulting in the distillation-free synthesis of high-purity aldehydes (>98% purity) by simple filtration, which deserves broader investigation for other porous organic materials.
Wang J, Cheng C, Deng J
… +3 more, Liu Y, Zhang B, Zhao BH
J Am Chem Soc
· 2026 Jun · PMID 42366826
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Unraveling the not-yet-definitive mechanism of the extensively studied cation effects in the electrocatalytic hydrogenation (ECH) process would provide methods to suppress competitive side reactions and address selectivi...Unraveling the not-yet-definitive mechanism of the extensively studied cation effects in the electrocatalytic hydrogenation (ECH) process would provide methods to suppress competitive side reactions and address selectivity issues, which have impeded the development of the electrosynthesis strategy. Here, taking electrochemical acetylene (CH) to ethylene (CH) hydrogenation (EAH) as a model case, the CH selectivity over commercial polycrystalline copper (p-Cu) exhibits a volcano-type trend with increasing cation radius (Li < Na ≈ K > Cs). The observed cation-dependent selectivity modulation results are attributed to the opposite trend in the hydrogen evolution reaction (HER) (inhibited) and CH dimerization (boosted) with increasing cation size. Further mechanistic studies reveal that the increased electronic interaction, asymmetric charge distribution, and increased discontinuity of the hydrogen bond network with increasing cation size result in easier activation and adsorption of CH feedstocks, accounting for the suppressed HER and enhanced coupling, respectively. Notably, the mechanism mentioned is also appropriate for explaining the highest C selectivity of CO electroreduction with Cs-containing electrolytes.
Cong YJ, Han XS, Long ZC
… +7 more, Zheng LM, Shi WQ, Hu F, Yun L, Liu X, Yang J, Wang QM
J Am Chem Soc
· 2026 Jun · PMID 42366810
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It is challenging to determine the structures of water-soluble metal nanoclusters due to the difficulty of their crystallization in aqueous media. As a consequence, the structures of many water-soluble nanoclusters are u...It is challenging to determine the structures of water-soluble metal nanoclusters due to the difficulty of their crystallization in aqueous media. As a consequence, the structures of many water-soluble nanoclusters are usually inferred from indirect models, which complicates the understanding of their structure-property relationships. We have developed a facile method to synthesize water-soluble gold nanoclusters with well-defined structures from esterified precursors. [CHN][Au(3-MeOOCCHC)] () has been synthesized using 3-methoxycarbonyl phenylacetylide as the protecting ligand, and its structure has been determined with single-crystal X-ray diffraction. These oil-soluble clusters can be converted to water-soluble in more than 90% yield via mild alkaline hydrolysis. Owing to the preservation of the metal core and superatomic electronic structure, the highly efficient photothermal performance of can be extended to water-soluble . We present a potentially generalizable strategy that provides a viable route to reduce reliance on indirect structural models in studies of water-soluble gold nanoclusters.
J Am Chem Soc
· 2026 Jun · PMID 42366804
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Copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a cornerstone reaction in modern chemistry. Although binuclear catalytic mechanisms have been widely proposed and certain binuclear complexes exhibit good activity,...Copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a cornerstone reaction in modern chemistry. Although binuclear catalytic mechanisms have been widely proposed and certain binuclear complexes exhibit good activity, asymmetric CuAAC still relies on the in situ assembly of copper salts with chiral ligands. Herein, guided by the postulated reaction mechanism, we employ a preassembled chiral binuclear copper catalyst with a well-defined chiral pocket to achieve efficient kinetic resolution of alkyne-functionalized azlactones with azides. This catalyst contains two copper(I) ions within a single chiral ligand framework, providing a rigid planar scaffold, stable coordination geometry, and a semicircular chiral cavity. Both triazole products and recovered azlactones are obtained in high enantiopurity and can be rapidly converted into chiral α-quaternary amino acid derivatives. This study establishes chiral binuclear copper complexes as an effective platform for enantioselective CuAAC.
J Am Chem Soc
· 2026 Jun · PMID 42366748
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The development of far-red light-activatable photolabile protecting groups (PPGs) is crucial for precision medicine applications, yet remains challenging due to the low energy of far-red light photons and the frequent co...The development of far-red light-activatable photolabile protecting groups (PPGs) is crucial for precision medicine applications, yet remains challenging due to the low energy of far-red light photons and the frequent compromise of aqueous solubility. While conditional PPGs activated by specific biochemical conditions offer enhanced spatial control, their scope is limited by the need for external triggers or heterogeneous enzyme expression. Here, we report a new class of dual-responsive PPGs based on a silicon-xanthenium scaffold that are activated by both acidic pH and far-red light. Through systematic structural modification, we developed pcSiR718-OH, a photocage with a low molecular weight (<500 Da) and a red-shifted absorption maximum at 718 nm. pcSiR718 exhibits efficient uncaging (ε × Φ = 184 Mcm) under mildly acidic conditions (pH 5.5-6.7) while remaining stable at physiological pH. Mechanistic studies reveal that photolysis can proceed via both homolytic and heterolytic pathways. We demonstrate the utility of this platform through the precise release of bioactive molecules─pomalidomide and gambogic acid─achieving spatiotemporal control over protein degradation in cellular models and tumor growth inhibition in a murine model. This work establishes a versatile strategy for designing environmentally responsive photocages for targeted therapy.
Wei C, Su Y, Zhu Y
… +13 more, Li R, Fang C, Xu W, Zhou Y, Xiao S, Bai J, Liu J, Shi J, Xiao Z, Gao M, Huang J, Li Q, Hong W
J Am Chem Soc
· 2026 Jun · PMID 42366736
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Understanding the local coordination environments and dynamic catalytic events at the scale of the active site is crucial for the precise design of efficient catalysts under operating conditions. Conventional characteriz...Understanding the local coordination environments and dynamic catalytic events at the scale of the active site is crucial for the precise design of efficient catalysts under operating conditions. Conventional characterizations often provide only average structural information on bulk catalytic materials, overlooking local site-specific behaviors. Here, we monitor conductance signatures consistent with local coordination changes and stepwise catalytic events at a single active site under catalytically relevant solution conditions. This approach allows us to infer a catalytic sequence, including adsorption, bond activation, intermediate formation, and product release, while elucidating microenvironment-induced coordination changes at this localized scale. We establish a quantitative correlation between local steric effects and catalytic activity in experiments and propose the creation of a local structure with low steric hindrance at the active site to enhance performance. Our findings highlight the potential of single-cluster characterizations for advancing the interpretation of molecular-level catalysis, offering new insights into catalytic material design and performance optimization.
Zhu J, Cao Z, Wang T
… +6 more, Qin W, Wu C, Gao L, Li J, Kong X, Peng X
J Am Chem Soc
· 2026 Jun · PMID 42366539
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Although they serve as the workhorse in the short-wavelength infrared window, performance of lead chalcogenide nanocrystals (NCs) in optoelectronic devices suffers from various atomic-level structural and electronic defe...Although they serve as the workhorse in the short-wavelength infrared window, performance of lead chalcogenide nanocrystals (NCs) in optoelectronic devices suffers from various atomic-level structural and electronic defects rooted in the facet-ligand interface. Considering the rock-salt structure, here we target the synthesis of PbSe NCs encased in eight (111) facets by introducing soluble chloride (or other halides) and alkanoate ions as mixed ligands in octadecene to release excessive strain within the conventional alkanoate ligand monolayer on the polar (111) facets. The resulting monodisperse octahedral PbSe NCs possess the defined (111) facets, as observed at a resolution of approximately one atomic layer by high-resolution transmission electron microscope (TEM), and a single facet-ligand coordination motif. The resulting NCs exhibit unique optical properties, formation of an orthorhombic three-dimensional superlattice, outstanding chemical stability against aerobic exposure, and excellent structural stability in solutions and thin films. As strong ligands, mixed alkanoate-chloride ligands yield small octahedral NCs─essential for high-efficiency photovoltaic devices─with high mass yields by controlling nucleation and growth. Results here reveal that ligand chemistry is the key toward atomically precise synthesis of colloidal NCs that are ideal for both fundamental research and technical applications.