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<i>p</i> ‐Benzoyl‐ <scp>l</scp> ‐phenylalanine as a Multifunctional Noncanonical Amino Acid in Synthetic Biology: Photoprobing, Photocatalysis, and Structural Programming for Biocontainment
ABSTRACT p ‐Benzoyl‐ l ‐phenylalanine (pBzF) is a widely used noncanonical amino acid (ncAA) that expands the chemical repertoire of proteins. Its benzophenone (BP) chromophore undergoes near‐quantitative intersystem crossing (ISC) to a triplet state, furnishing a highly efficient, site‐addressable photoreactive handle. Beyond photochemistry, the bulky, hydrophobic side chain introduces distinct steric and electronic effects that enable new reactivity in protein active sites. Genetic incorporation of pBzF in vivo, including directed evolution, has unlocked applications ranging from site‐specific photo‐crosslinking for interaction mapping to engineering antibody fragments, sharpening monoclonal antibody (mAb) epitope recognition, and creating protein‐based photocatalysts. pBzF has also proved powerful for mechanistic studies by stabilizing short‐lived intermediates. More recently, pBzF‐containing proteins have been leveraged in light‐driven transformations, including [2+2] photocycloadditions, deracemizations, and dehalogenations, and in the construction of artificial photosynthetic systems. This review critically discusses these advances and establishes pBzF as a versatile photochemical and structural motif for building proteins with non‐natural, light‐responsive, and catalytically competent functions.
Quasi‐One‐Dimensional Perovskite Single Crystals Enabling Decoupled Ionic–Electronic Transport for Sensitive and Stable X‐ray Detection
ABSTRACT Metal halide perovskites are promising candidates for low‐cost and sensitive x‐ray detection. However, the existing perovskite materials with diverse composition and dimensionality encounter an intrinsictrade‐off between carrier collection and ion migration, posing a critical challenge for high‐energy x‐ray detection. Here, we demonstrated that the quasi‐one‐dimensional perovskite of cystamine lead iodide featuring corner‐sharing [Pb 5 I 22 ] chains chain and small interchain spacing along edge‐on orientation enables efficient carrier collection and blocked ion migration simultaneously, and thus largely decouple the electronic and ionic transport pathways. The as‐grown single crystals yield a large mobility‐lifetime product of 4.35 × 10 −4 cm 2 V −1 , and a high activation energy for ion migration of 0.94 eV. Therefore, an impressive x‐ray sensitivity of 1.42 × 10 5 µC Gy −1 cm −2 (average x‐ray energy 42.7 keV) are obtained in quasi‐one‐dimensional perovskite. Under harsh conditions, such as continuous radiation, high electric fields, and high temperatures, the device exhibits excellent operational stability. As a proof of concept, the robust integration of a quasi‐one‐dimensional perovskite with a thin‐film transistor backplane for x‐ray imaging was achieved. This study offers innovative insights into the regulate the structural dimensions of materials for sensitive and stable x‐ray detection.
Photoswitch Mediated Electron Highway Driving Direct Pollutant‐to‐Oxidant Electron Transfer in Ultrafast Fenton‐Like Reactions
ABSTRACT Traditional heterogeneous photocatalytic systems coupled with oxidant activation hold great promise for environmental remediation but are constrained by radical scavenging and nonselective oxidation. Here, we introduce an overlooked photoswitch‐mediated electron transfer (PSMET) mechanism that circumvents reactive oxygen species by enabling direct, ultrafast electron transfer from pollutants to oxidants through a photoactive mediator. Using environmentally benign bismuth oxyiodide as a model catalyst under visible‐light irradiation, we achieve unprecedented degradation rates for various electron‐rich pollutants such as sulfamethoxazole (t 1/2 <2.0 min). This mechanism exhibits pollutant‐dependent oxidant utilization mode and selective pollutant degradation characteristics. Mechanistic analyses reveal the formation of a high‐potential electron‐transfer pathway activated by photoexcitation, directly coupling pollutant oxidation to oxidant reduction within a single electron‐transfer cycle. Frontier molecular orbital calculations further demonstrate that the narrow bandgap and p‐type semiconductor characteristics selectively facilitate electron extraction from contaminants to oxidants. Remarkably, this PSMET mechanism displays universal applicability with diverse oxidants, maintaining >98% pollutant removals even in complex aqueous matrices and continuous‐flow systems. Furthermore, the mechanism allows precise optical control over reaction initiation and termination, offering unparalleled spatiotemporal regulation for sustainable wastewater treatment. Our findings redefine photocatalytic oxidation paradigms and open new pathways toward energy‐efficient, optically programmable, and environmentally sustainable remediation technologies.
First Principles Identification of Active Sites in Heterogeneous Catalysis: A Case Study on Zn <sub>x</sub> Cr <sub>y</sub> O <sub>z</sub> for Syngas Conversion
ABSTRACT Discovering next‐generation heterogeneous catalysts calls for embracing the full complexity of active site formation under realistic conditions. Here, we develop a robust machine learning potential (MLP)‐aided computational framework that integrates realistic preparation and reaction conditions to effectively track the formation of active sites and decipher structure‐activity relationships. Using syngas conversion over the Zn x Cr y O z system as a demonstration, we identified that the system preferentially segregates into ZnO and ZnCr 2 O 4 phases, with ZnO forming a monolayer on ZnCr 2 O 4 surfaces under preparation conditions. Under reaction conditions, by deploying CH─O bond dissociation as a descriptor, we found that the ZnO/ZnCr 2 O 4 (100) surface is the active surface. Crucially, we pinpoint geometrically linked oxygen vacancy pairs as the true active sites. Full microkinetic analyses conducted on these active sites yield kinetic results that align well with experimental observations. Beyond elucidating the active structure, a model for designing oxide/oxide catalysts to achieve high activity is generalized, opening new pathways for accelerating catalyst discovery across a wide range of reactions.
Correlating Structure Change With Magnetic Ordering and Spin Fluctuation During Delithiation of Transition Metal Layered Oxide
ABSTRACT Current Li‐ion battery technology relies on Li + insertion/extraction coupled with electron gaining/loss at both cathodes and anodes. Although extensive efforts have been devoted to studying the structure change of cathode materials with Li + extraction/insertion, changes in the magnetic properties arising from the accompanying redox processes have been largely overlooked. Here, we systematically investigate both the structure evolution and magnetic‐property changes during the delithiation of the representative layered oxide LiCoO 2 , by combining the operando synchrotron‐based x‐ray diffraction with dedicated magnetic measurements. We construct a magnetic phase diagram as a function of Li content x in Li x CoO 2 , which closely mirrors the corresponding structure evolution diagram. The results reveal a series of complicated magnetic transitions upon Li extraction: paramagnetic → antiferromagnetic → paramagnetic → diamagnetic → paramagnetic. Moreover, the variation in the effective magnetic moment of Co 4+ is strongly correlated with local structural changes within the CoO 6 octahedra, indicating that the Co 4+ spin‐state fluctuation may play an important role in the structure evolution and electrochemical performance. These findings help close a critical gap in understanding structure‐magnetism coupling during the electrochemical cycling and may inspire the design of new layered oxide cathodes from a spin‐electronics perspective.
Supramolecular Nanoconfinement‐Accelerated Synthesis of Two‐Dimensional Styrenic Polymers Boosting Proton Conductivity in Nafion‐doped Membranes
ABSTRACT Two‐dimensional (2D) covalent polymers offer environmental stability, surface area, and mechanical resilience, but preparation of functional, freestanding 2D polymers remains challenging. Inspired by phospholipid bilayers, we developed a bilayer self‐assembly strategy for 2D covalent polymer synthesis with tailored functionalized surface. Ionic amphiphilic styrene monomers employ intramolecular face‐to‐face stacking, inducing a folded monomer conformation that achieves a critical packing parameter near unity. This drives 2D nanosheet formation in basic aqueous solution. Concurrent electrostatic repulsion enabled spontaneous exfoliation. In situ radical polymerization within preorganized framework, accelerated by nanoconfinement effect, converted supramolecular assemblies into covalent bilayer polymers with 95% monomer conversion. Incorporating sulfonic acid‐functionalized 2D polymers (0.66 wt%) into Nafion D2020 membrane enhanced mechanical strength and proton conductivity at room temperature. Fuel cell testing (70°C, 100% RH) demonstrated increased open‐circuit voltage (1.00 V vs. 0.96 V), suppressed hydrogen permeation, elevated peak power density (678.9 vs. 454.6 mW·cm −2 ), and reduced ohmic resistance (25.2 vs. 55.1 mΩ).
Hydrogen‐Bond Network‐Directed Controllable Assembly of Stable Cyanine J‐Aggregates for Long‐Term and High‐Contrast In Vivo Imaging
ABSTRACT Optical probes based on near‐infrared region (NIR) small‐molecule dyes have emerged as an indispensable tool for contemporary in vivo biomedical research. Nevertheless, the majority of the reported NIR small‐molecule probes are plagued by issues such as poor stability, short excitation wavelength, and inadequate lesion retention ability, all of which significantly hinder accuracy in vivo imaging. Herein, we introduce a strategy to construct ultra‐stable and optically controllable J‐aggregated cyanine ( JCy ) with rapid in vivo self‐assembly ability by incorporating carboxyl groups and adjusting the alkyl chain length of classical heptamethine cyanine dye. Single‐crystal x‐ray diffraction analysis reveals that the strong hydrogen bonds formed by carboxyl groups enable JCy dyes to assemble into Z‐shaped dimers and the dimers interlocking “linear supramolecular arrays (LSA)” within the crystal. These LSAs then undergo a tight and ordered J‐aggregation through the electrostatic interactions, C─H⋯O hydrogen bonds and π–π interactions. This unique J‐aggregation mechanism confers JCy dyes with carrier‐independent in vivo self‐assembly and superior stability. As a proof‐of‐concept, we selected JCy‐Bu , which exhibits low concentration dependence, remarkable resistance to protein interference, and outstanding photochemical stability, for in vivo biological study, and have achieved long‐term, high‐contrast in situ imaging of mouse gastric and tumor tissues.
Fluorinated Glycan Frameshifts: Automated Synthesis Expedites the Study of Glycan‐Protein Interactions by <sup>19</sup> F‐BioNMR
ABSTRACT Given the prominence of 19 F‐bioNMR in structural research, fluorinated glycan frameshifts hold enormous potential in studying carbohydrate‐protein interactions. To contribute to this field, the synthesis of selectively C‐2 fluorinated glycans related to the O3b antigen of Klebsiella pneumoniae is disclosed, and their interactions with the lectin Concanavalin A (ConA) are interrogated spectroscopically. Automated glycan assembly (AGA) was employed to expedite construction in which the C(sp 3 )‐F bond was leveraged to control stereoselectivity of α‐mannosylation. Subsequent 19 F‐BioNMR analysis of binding to ConA allowed determination of the respective IC 50 and K D values; this revealed a conspicuous frameshift‐dependency in which one pattern dominated. Collectively, this study advocates for the strategic utilisation of the C(sp 3 )‐F bond in the design, construction, and analysis of probes to interrogate ubiquitous mannose‐binding lectins with therapeutic relevance.
Terminal Cyanate in Stabilizing Mononuclear Cu(III) Complex: Room Temperature Preparation, Characterization, and Reactivity
ABSTRACT Great efforts have been made to generate new types of late transition metal oxidants by tuning terminal ligands. These metal oxidants play a key role to activate and functionalize C─H bond via proton coupled electron transfer (PCET) mechanism. Herein, we have developed a unique oxidant, high valent metal‐cyanate, under ambient conditions. The high valent complex [(L)Cu III (NCO)] ( 2 , H 2 L ═ N,N′‐(2,6‐diisopropylphenyl)‐2,6‐pyridinedicarboxamide) was prepared from [(L)Cu II (NCO)]Bu 4 N ( 1 ) by one electron oxidation and both complexes were characterized by x‐ray crystallography and UV–vis, 1 H/ 13 C NMR, Raman, FT‐IR and EPR spectroscopies, and ESI–MS. 2 reacted with C─H and O─H bond via hydrogen atom transfer mechanism, as evidenced by kinetic data, product analysis and computational findings, and reaction rates are comparable to some reported reactive metal oxidants. Fascinatingly, 2 performed direct C─N bond formation by activating C─H bond and cyanate group transfer reactions. We observed solvent dependent reactions of 2 . Our results found a new class of metal oxidant for strong C─H bond functionalization. We believe that high valent metal‐cyanates could open new avenues for very interesting coordination and bioinspired oxidation chemistry due to electronic, resonating, and ambidentate properties of terminal cyanate ligand with potential two different proton accepting sites (N and O).
Confined Cu <sub>111</sub> Nanolaminates as a Single‐Phase Nanoreactor for Efficient Urea Electrosynthesis
ABSTRACT Modern electrocatalysis typically involves multi‐species cascade systems, imposing stringent requirements on catalysts to exhibit multi‐component and multifunctional characteristics. Such complexity poses great challenges for identifying and understanding the structural and functional nature of the true active phase. Herein, we report the formation of Cu 111 nanolaminates confined within the interface of Cu 1.94 S/In 2 S 3 heterojunction via in situ electrochemical reconstruction. The synthesized Cu 111 nanolaminates act as a single‐phase co‐activating nanoreactor to preferentially adsorb carbon dioxide (CO 2 ) and cascade N‐intermediates, enabling C─N coupling for urea synthesis within an ultra‐low and distinct potential window. The optimized Cu 1.94 S/Cu 111 /In 2 S 3 catalyst achieves a urea yield rate of 11823.65 µg h −1 mg Cu111 −1 and an exceptionally high Faradaic efficiency of 69.34% at ‐0.35 V versus the reversible hydrogen electrode in a flow cell, surpassing all previously reported transition metal electrocatalysts. In situ spectroscopic analyses and theoretical calculations reveal a favorable reaction pathway and nanoconfined synergy on the Cu 111 nanolaminates, where CO 2 is initially anchored and reduced to *CO and cascaded *NO 2 undergoes C─N coupling to form the key *CONO 2 intermediate toward urea. This study unveils the true active phase within a complex heterostructure electrocatalyst, which also provides new insights into the rational design of advanced electrocatalysts for other energy and environmental applications.
Dynamic Spin Governing Asymmetric Coordination Fields in Trimetallic Single‐Atom Catalysts for Optimal Oxygen Reduction
Abstract Single‐atom catalysts demonstrate theoretically superior oxygen reduction reaction (ORR) kinetics, the limited dynamic adaptability, however, poses a giant challenge to meet the multi‐step proton‐coupled electron transfer (PCET). Herein, we propose a “ Dynamic Spin Engineering ” strategy for the rational design of tri‐metallic single‐atom catalysts (FeZnTM‐TACs) featuring asymmetric coordination fields (FeN 4 ZnN 3 TMN 4 ). Leveraging electron synergy and spatial functional decoupling among heterometallic sites, the optimized FeZnMn‐TACs exhibit exceptional ORR performance ( E 1/2 = 0.93 V versus RHE) and ultra‐long stability (Δ E 1/2 = 24 mV after 90,000 cycles). Through operando X‐ray absorption fine structure and spin‐polarized density functional theory, we unveil the scalability of a ternary synergy encompassing dynamic reconstruction, charge compensation and spin‐state transition, clarifying the roles of electron donors at the ZnN 3 sites and proton supply at MnN 4 sites. Dynamic FeN x C y evolution triggers a spin‐state transition from medium spin (MS = 1.5) to low spin (LS = 1.0), accompanied by the d xz / d yz orbital occupancy degree from 50% to 100%. As a consequence, we synergize the dual optimization of *OOH formation and *OH desorption in PCET. Moreover, our work atomically deciphers the spin redistribution mechanism driven by dynamic reconstruction, establishing a new paradigm for designing self‐adaptive electrocatalysts that ultimately unify ultrahigh activity with operational stability.
Protective Shield for Interfacial Cu <sup>+</sup> /Cu <sup>0</sup> Sites Enhances Multicarbon Production Toward Electrochemical Reduction of Carbon Dioxide
ABSTRACT The interface of Cu + /Cu 0 is a promising active site for multi‐carbon (C 2+ ) products towards the electrochemical reduction of carbon dioxide (CO 2 RR), whereas the cathodic environment commonly destroys this site by Cu + reduction. Herein, we introduced the acid radical of trimesic acid (BTC) by electrochemical reconstruction as a “protective shield” for the stabilization of the Cu + /Cu 0 interface. The BTC‐stabilized Cu + /Cu 0 interface displayed a Faradaic efficiency (FE) of 86.4 ± 2.4% for C 2+ products at 600 mA cm −2 towards CO 2 RR in neutral electrolyte, with the retention of Cu + /Cu 0 interface during the reaction. Such stabilization effect by BTC shield was attributed to the preferential trapping of the *H intermediates and decreased *H‐induced transfer and corrosion for Cu + . The BTC‐stabilized Cu + /Cu 0 interface displayed a distinct asymmetry coupling path between *CO and *COH, which lowered the energy barrier of C 2+ production. This work represents a new strategy for the stabilization of interfacial Cu + /Cu 0 sites towards CO 2 RR.
Distance‐Dependent Energy Transfer Between Organic Fluorophores and Single‐Walled Carbon Nanotubes
ABSTRACT Single‐walled carbon nanotubes (SWCNTs) are promising optical biosensing platforms due to their intrinsic near‐infrared fluorescence and environmental sensitivity. While DNA‐SWCNT hybrids have been widely studied, the structural arrangement of double‐stranded DNA (dsDNA) on SWCNTs and its impact on exciton–fluorophore interactions remain insufficiently characterized. Here, we introduce carbon nanotube energy transfer with vertical nucleic acids (CNETvNA), in which fluorophores are positioned at defined distances from SWCNTs using guanine‐defect anchored capture sequences hybridized with complementary oligonucleotides. By systematically varying the duplex length from 12 to 24 base pairs, we probe the distance dependence of dye–SWCNT interactions at the single‐molecule level. Fluorescence lifetime imaging microscopy reveals efficient quenching of ATTO542 and ATTO643 dyes, with lifetime distributions reflecting heterogeneous duplex conformations. Molecular dynamics simulations demonstrate that dsDNA duplexes adopt a predominantly perpendicular orientation relative to the SWCNT axis, with increasing tilt and conformational variability at longer lengths. Combining experimental and computational results, we establish a distance dependence of d − 5 with 7.4 ± 0.7 nm for 50% quenching efficiency, consistent with theoretical predictions for point dipole donors and 1D acceptors. These findings provide structural insights into DNA‐SWCNT conjugates and establish CNETvNA as a rational design principle for SWCNT‐based biosensors.
Expeditious Synthesis of 2‐Deoxy‐2‐perfluoroalkyl Glycosides
ABSTRACT In carbohydrate‐based drug discovery, fluorine‐containing substituents are widely used to enhance pharmacodynamic and pharmacokinetic profiles. However, the precise incorporation of C(sp 3 )‐perfluoroalkyl moieties at the C2 position of sugar scaffolds remains a significant synthetic challenge. In this study, we report a highly efficient and cost‐effective protocol for the synthesis of 2‐deoxy‐2‐perfluoroalkyl glycosides from readily available glycals. This protocol demonstrates exceptional substrate generality, encompassing glucal, galactal, rhamnal, sialic acid, and arabinofuranose derivatives. More importantly, this platform enables the efficient synthesis of diverse C ‐, N ‐, and O ‐glycosides (over 50 examples) under gold(I)‐catalyzed conditions, including the synthesis of previously inaccessible 2‐deoxy‐2‐CF 3 ‐substituted nucleoside analogues. Additionally, photocatalytically generated 2‐deoxy‐2‐CF 3 glycosyl anomeric radicals readily undergo Giese‐type additions to alkenes, affording alkylated glycosides, or engage in cross‐coupling with aryl bromides to deliver antidiabetic drug candidates. Preliminary biological evaluations indicate that 2‐deoxy‐2‐CF 3 ‐modified glycosides exhibit enhanced pharmacological properties, underscoring the translational potential of this synthetic technique for advancing carbohydrate‐based therapeutics.
Near‐Infrared Photothermal Polymerization of Thioctic Acid Triggered by Polyoxometalate Crosslinker
ABSTRACT The monomer conversion rate of thioctic acid (TA) and the cross‐linking degree of polymer chains significantly influence the performance of materials, making them important research topics. Herein, by selecting a reduced polyoxometalate complex modified with 1‐allylpyridinium cations, which exhibits strong near‐infrared (NIR) light absorption capability, as both photothermal agent and cross‐linking agent, the polymerization of TA is successfully achieved under NIR light irradiation. The incorporation of photothermal agents results in their multiple dispersion throughout the polymerization matrix, facilitating uniform internal heat generation and inside‐out thermal diffusion. This mechanism significantly shortens the heat conduction pathway and effectively mitigates the inhomogeneous polymerization typically caused by temperature gradients inherent in conventional heating methods. Moreover, the C─S bonds formed via the reaction between the C═C groups and the disulfide linkages of TA not only suppress depolymerization but also serve as robust anchoring sites within the polymer network. By tuning the monomer composition, TA‐based adhesives and elastomers are successfully fabricated, exhibiting excellent re‐processability through NIR‐triggered remelting or repair. The NIR‐light‐regulated polymerization approach offers distinct advantages, including operational simplicity, rapid response, and spatiotemporal control, thereby presenting a promising strategy for the synthesis of high‐performance TA‐based polymers.
Spatial Mapping of Membrane Protein Interactions Using a DNA Origami Rubbing
Abstract Revealing the protein–protein interactions (PPIs) of membrane proteins is as challenging as their structural reconstruction, primarily because the molecular structures and related PPIs of membrane proteins are highly dependent on the bio‐membrane where they are situated. DNA origami offers a platform for manipulating molecules with nanoscale precision. Herein, we used a square‐like DNA origami, refer to as DNA origami rubbing, to map the two‐dimensional distribution of membrane proteins in situ. Through artificial models and cell studies, we correlated the efficiency of barcode recording of DNA origami rubbings with the distance between adjacent proteins, and we observed that the frequency of adjacent proteins mapped by DNA origami rubbings was correlated to the abundance of the bait protein. We demonstrated that the DNA origami rubbing was able to reflect the distribution change of adjacent proteins caused by adding the ligand of bait protein. Our results suggested that the DNA origami rubbing can serve as a powerful tool in the field of protein interactomics.
Modulating Electron Delocalization Structure in Covalent Organic Frameworks Through Conjugation and Hybridization to Boost Li‐ion Migration Dynamics
ABSTRACT The inherent factors influencing the growth of lithium (Li) dendrites and the kinetics of Li + migration in polymer electrolytes lie in the electron cloud density distribution in the electrolyte. Localized electrons accumulation can trigger the uneven Li + deposition, ultimately leading to battery failure. To address this critical challenge, the concept of p–π conjugation and B–O sp 2 hybridization is innovatively incorporated into covalent organic frameworks (COFs) to mitigate local interfacial Li + accumulation and improve Li + migration kinetics in electrolytes by electron delocalization. Furthermore, perfluoroalkyl group with virtues of superior electron regulating capabilities and improved electrochemical‐window, is strategically grafted to better match high‐voltage cathodes. Under the synergistic role of electron regulation, the electrolyte with pπ–sp 2 ‐COF significantly improves overall electrochemical performance of solid‐state batteries. Thus, regulating electron density via p‐π conjugation and B‐O sp 2 hybridization promises to open new avenues for the development of COFs‐modified polymer electrolytes in solid‐state batteries.
Magnesiation of Phenol Derivatives Catalyzed by a Rhodium─Aluminum Complex
ABSTRACT Here we describe the generation of aryl Grignard reagents from phenol derivatives via C─O bond activation cooperatively catalyzed by Rh─Al heterobimetallic complexes. We discovered that the electron‐rich arylmagnesium reagents could be efficiently prepared from the corresponding aryl carbamates, whereas the π‐extended arylmagnesium reagents were obtained from the corresponding aryl ethers. This methodology enables the efficient conversion of a broad range of phenol derivatives into the corresponding Grignard reagents, which can subsequently react with various electrophiles to yield a diverse array of organic compounds.
A Redox‐Active Mesoporous Cobalt–Pyrazolate Framework for Reversible O <sub>2</sub> Sorption
Abstract Expanding pyrazolate metal–organic frameworks (MOFs) beyond microporous architectures is a formidable synthetic challenge, as the strong and directional M–N bonds impose strict geometric constraints that hinder the integration of mesoporosity and active sites. Such limitations have restricted the structural diversity of pyrazolate MOFs compared with their carboxylate analogues, despite the former offering superior chemical stability and fantastic performance in gas storage, separation, and catalysis. Here we present mesoporous BUT‐45 as the first example of csq ‐type pyrazolate MOF, which was constructed from the low‐symmetry (C s ) tetra‐pyrazolate ligand 1,3,6,8‐tetra(1 H ‐pyrazolate‐4‐yl)‐9 H ‐carbazole (CTP 4– ) and 8‐connected Co 6 clusters (D 2h ). Interestingly, the presence of rich active Co sites enables instantaneous O 2 chemisorption at ambient temperature in BUT‐45, and good framework stability allows this process to be fully reversible. Single‐crystal x‐ray diffraction and in situ spectroscopy analyses provide structural insights into the as‐synthesized, O 2 ‐loaded, and regenerated phases, revealing the mechanism of Co–O 2 adduct formation and demonstrating complete reversibility via hydrazine hydrate reduction. This work highlights how reticular chemistry can map target nets from carboxylate to pyrazolate, while offering desired properties and direct visualization of redox chemistry in MOFs.
Methyl Asymmetric Interference‐Enhanced Dipole–Dipole Interaction for High‐Performance Potassium–Graphite Battery Electrolyte Design
ABSTRACT Potassium‐ion batteries are the only new alkali metal battery system, apart from lithium‐ion batteries, that can directly use graphite as the anode. However, the development of potassium–graphite batteries has been restricted due to the lack of high‐voltage electrolytes compatible with graphite anodes. To address this issue, a graphite‐compatible high‐voltage electrolyte is designed based on methyl asymmetric interference‐enhanced dipole–dipole interactions. The formulated electrolyte achieves an initial Coulombic efficiency of 86.5% by reducing the desolvation energy of K + ions and forming a sulfur‐rich inorganic solid electrolyte interface. At a low current density of 1 µA cm −2 , the maximum stable electrochemical window of the electrolyte reaches 4.6 V, which is compatible with the currently used Prussian blue analogue cathodes. Notably, the potassium–graphite battery with K 1.92 Fe[Fe(CN) 6 ] 0.94 ·0.5H 2 O as the cathode and untreated graphite as the anode can deliver an energy density of 265.6 Wh kg −1 (based on the total mass of cathode and anode) with a capacity retention of 81.3% after 600 cycles. When K 1.68 Mn[Fe(CN) 6 ] 0.92 ·1.36H 2 O is used as the cathode, the energy density can reach 306.2 Wh kg −1 . A five‐stacked pouch full cell with a capacity of ∼24 mAh can rapidly drive a small motor, demonstrating the application potential of the electrolyte.