Browse Articles

Introducing the Aziridination of Fluorinated Olefins by Metal‐Catalyzed Nitrene Transfer

AbstractAfter decades of development of the metal‐catalyzed nitrene transfer reactions to olefins, examples involving the use of fluorinated olefins is yet unknown, despite the current importance of fluorocompounds. Herein we describe the use of copper‐ and silver‐based catalysts for a general protocol that converts α‐ or β‐fluoro olefins into the corresponding aziridines in high yields.

Isolated and Paired Metal Sites in Zeolites Using Solid‐State Ion Exchange

AbstractIsolated and paired extraframework transition metal cations in zeolites are emerging as top candidates for numerous applications, including, but not limited to, selective methane oxidation to methanol, selective catalytic reduction of nitrogen oxides, propane dehydrogenation, propylene epoxidation, and direct air capture of carbon dioxide. Importantly, these well‐defined heterogeneous catalysts offer parallels with molecular and metalloenzyme catalytic active sites. Aqueous‐phase ion exchange (APIE) is the most common synthesis technique to obtain these catalysts. Solid‐state ion exchange (SSIE) is an often overlooked technique that offers synthetic advantages compared to APIE. Thus, recent advances in solid‐state synthesis strategies merit contemporary contextualization. In this minireview, we describe the basic principles, methods, mechanisms, challenges, and advances in solid‐state ion exchange in the context of well‐defined transition metal cation active sites located in extraframework positions of the zeolite.

Biomimetic Hierarchical Construction of Anti‐Tumor Polyoxopalladates for Cancer Therapy

AbstractInspired by the construction scheme of biomacromolecules, a hierarchical assembly based on the lacunary polyoxopalladate (POP) of [SrPd12O6(OH)3(PhAsO3)6(OAc)3]4− (SrPd12) has been achieved. As a structurally programmable molecular building block, SrPd12 is used to evolve from monomer via dimer to supramolecular aggregates in a controlled manner. In such process, the open‐shell‐type monomers are covalently integrated into bowl‐ or cage‐like dimers via a direct or indirect splicing strategy. Upon that, hydrogen bond and hydrophobic effects are further hired to fabricate supramolecular aggregates of varied host–guest archetypes, thereby completing a hierarchical construction. In consideration of the combined advantages of noble metals and polyoxometalates in cancer treatment, both in vitro and in vivo anti‐tumor assays of these SrPd12‐derived POPs were studied in detail. A structure‐dependent anti‐tumor activitywas observed, originating from an imbalance of damage and repair of DNA as anti‐tumor mechanism.

Tailored 3‐Alkoxy‐<i>N</i>,<i>N</i>,<i>N</i>,2,2‐Pentamethylpropan‐1‐Ammonium <i>Bis</i>(trifluoromethylsulfonyl)Imide Ionic Liquids for Room‐Temperature Fluoride‐Ion Batteries

AbstractTwo novel liquid electrolytes for room‐temperature fluoride ion batteries are presented. These electrolytes are based on ionic liquids with quaternary ammonium cations 3‐methoxy‐N,N,N,2,2‐pentamethylpropan‐1‐aminium (MNPA) and N,N,N,2,2‐pentamethyl‐3‐(2,2,2‐trifluoroethoxy)propane‐1‐aminium (NPPA) combined with a bis(trifluoromethylsulfonyl)‐imide (TFSI) counterion. Quaternary ammonium fluorides can be added at concentrations up to 0.7 M to a functional fluoride electrolyte with a total diffusivity of 4.99 × 10−12 m2 s−1, a viscosity of 260 mP⋅s and a wide operational voltage range exceeding 5.4 V. The liquid ion electrolyte with the MNPA cation supports stable fluoride ion shuttling for up to 100 h.

Marvin Parasram

Synergistic Solvent and Composition Engineering of Perovskites for Tandems on Industrial Silicon

AbstractWide‐bandgap perovskites based on mixed formamidinium−cesium cation and iodide−bromide halide are promising materials in the top cells that are well‐matched with crystalline silicon bottom cells to construct efficient tandem photovoltaics. Nevertheless, mixed cation−halide perovskite films with submicron film thickness suffer from poor crystallinity with inhomogeneous and undesirable phases, owing to the presence of multiple pathways of crystal nucleation and phase transition. Herein, we propose a synergistic solvent and composition engineering (SSCE) strategy to regulate the solvated phases and manipulate the transition pathways simultaneously. The resultant mixed cation−halide perovskite film shows optimizing crystallization and desired phase structure with suppressed nonradiative recombination and improved phase stability under aging stresses. Consequently, the SSCE strategy enables the tandem cells based on industrially ultrathin silicon wafers (120 µm) to achieve a certified stabilized power conversion efficiency of 31.0%. Those encapsulated devices maintain 90% of their initial performance after 1200 h continuous operation.

Enhanced <i>p–d</i> Orbital Coupling in Unconventional Phase RhSb Alloy Nanoflowers for Efficient Ammonia Electrosynthesis in Neutral Media

AbstractPhase control provides a promising approach for physicochemical property modulation of metal/alloy nanomaterials toward various electrocatalytic applications. However, the controlled synthesis of alloy nanomaterials with unconventional phases remains challenging, especially for those containing both p‐ and d‐block metals. Here, we report the one‐pot synthesis of ultrathin RhSb alloy nanoflowers (NFs) with an unconventional 2H phase. Using 2H RhSb NFs as an electrocatalyst for nitrite reduction reaction in neutral media, the optimal NH3 Faradaic efficiency and yield rate can reach up to 96.8% and 47.2 mg h−1 mgcat−1 at −0.3 and −0.6 V (vs. reversible hydrogen electrode), respectively. With 2H RhSb NFs as a bifunctional cathode catalyst, the as‐assembled zinc‐nitrite/methanol batteries deliver a high energy efficiency of 96.4% and improved rechargeability with 120‐h stable running. Ex/in situ characterizations and theoretical calculations have demonstrated that the phase change of RhSb from face‐centered cubic (fcc) to 2H has optimized the electronic structure through stronger interactions between Rh and Sb by p–d orbital couplings, which improves the adsorption of key intermediates and reduces the reaction barriers of nitrite reduction to guarantee the efficient electrocatalysis. This work offers a feasible strategy of boosting the electrocatalytic performance of alloy nanostructures by integrating phase control and p–d orbital coupling.

Symmetry‐Breaking Strategy Yields Dopant‐Free Small Molecule Hole Transport Materials for Inorganic Perovskite Solar Cells with 20.58% Efficiency and Outstanding Stability

AbstractInorganic perovskites are known for their excellent photothermal stability; however, the photothermal stability of all‐inorganic n‐i‐p perovskite solar cells (PSCs) is compromised due to ion diffusion and free radical‐induced degradation caused by the use of doped spiro‐OMeTAD hole transport materials (HTMs). In this study, two isomeric donor–acceptor–donor (D–A–D) type small molecules, namely HBT and HiBT, were developed and used as dopant‐free HTMs, using 2,1,3‐benzothiadiazole or benzo[d][1,2,3]thiadiazole as acceptor moieties. The HiBT molecule, with its symmetry‐breaking features, exhibits a large dipole moment, enhanced coordination‐active sites, and a well‐aligned energy level structure, all of which contribute to passivating perovskite surface defects and improving free charge separation. As a result, inorganic CsPbI3 PSCs with HiBT HTM achieved an impressive power conversion efficiency (PCE) of 20.58%, the highest reported for dopant‐free HTM‐based inorganic PSCs. Moreover, the enhanced hydrophobic properties of HiBT molecules, coupled with their ability to passivate perovskite surface defects, contribute to significantly improved device stability. The unencapsulated devices based on HiBT HTM retained over 83% and 80% of their initial efficiency after being stored at 85 °C for 50 days and undergoing maximum power point (MPP) tracking at 85 °C for 1100 h, respectively. These results highlight that the symmetry‐breaking strategy is an exceptionally effective approach for designing efficient, dopant‐free small molecule HTMs, significantly contributing to both the high efficiency and enhanced stability of all‐inorganic PSCs.

Back Cover: Quantum Mechanical Tunnelling Probes With Redox Cycling for Ultra‐Sensitive Detection of Biomolecules (Angew. Chem. Int. Ed. 23/2025)

Linkages Chemistry of Covalent Organic Frameworks in Photocatalysis and Electrocatalysis

AbstractCovalent organic frameworks (COFs) have emerged as promising candidates for electrocatalysis and photocatalysis applications due to their structurally ordered architectures and tunable physicochemical properties. In COFs, organic building blocks are linked via covalent bonds, and the structural and electronic characteristics of COFs are critically governed by their linkage chemistry. These linkages influence essential material attributes including surface area, crystallinity, hydrophobicity, chemical stability, and the optoelectronic behavior (e.g., photoelectron separation efficiency, electron conductivity, and reductive activity), which collectively determine catalytic performance in energy conversion systems. A systematic understanding of linkage engineering in COFs not only advances synthetic methodologies but also provides innovative solutions to global energy and environmental challenges, thereby accelerating the development of sustainable technologies for clean energy production and environmental remediation.

Photocatalytic Generation of a Ground‐State Electron Donor Through Water Activation

AbstractElectron donors that can be excited to higher energy states through light absorption can achieve oxidation potentials as low as −3.0 V (vs. SCE). However, ground‐state organic electron transfer reagents operating at such potentials remain underdeveloped, often necessitating multi‐step syntheses and elevated reaction temperatures for activation. The longer lifetime of ground‐state reagents is an advantage compared to most photoexcited single‐electron reductants, which typically have relatively short lifetimes. In this study, catalytically generated phosphine oxide radical anions derived from phosphines and water applying redox catalysis are introduced as highly efficient single‐electron reductants. The in situ generated radical anions are capable of reducing electron‐rich aryl chlorides at potentials as low as −3.3 V (vs. SCE). Cyclic voltammetry studies and DFT calculations provide valuable insights into the behavior of these phosphorus‐based ground‐state electron donors. These findings do not only expand the chemistry of phosphoranyl radicals but also unlock the potential of in situ generated organic ground state electron donors that reach potentials comparable to elemental potassium.

Asymmetric Synthesis of Noradamantane Scaffolds via Diphenylprolinol Silyl Ether‐Mediated Domino Michael/Epimerization/Michael (or Aldol)/1,2‐Addition Reactions

AbstractTopologically unique chiral noradamantanes are synthesized using a diphenylprolinol silyl ether‐mediated domino Michael/epimerization/Michael/1,2‐addition or Michael/epimerization/aldol/1,2‐addition reaction with excellent enantioselectivity in a single reaction vessel. Three carbon–carbon bonds are formed, and six chiral centers, including one all‐carbon quaternary center, are generated, five of which are fully controlled. These functionalized noradamantanes are 3D, cage‐like molecules that can serve as valuable chiral building blocks for drug design.

Regioselective Nickel‐Catalyzed Hydroarylation of <i>gem</i>‐Difluoroalkenes for the Synthesis of the ArCF2−${\rm{ArCF}}_{{2}^{-}}$ Moiety

AbstractThe incorporation of fluorine and fluorinated functional groups into organic molecules alters their physicochemical properties, thereby facilitating the advancement of novel therapeutics, agricultural chemicals, biological probes, and materials. Nevertheless, there remains a deficiency of methodologies for the catalytic synthesis of certain significant fluorine‐containing groups, such as , under mild conditions utilizing earth‐abundant metals. Herein, we report a method for the regioselective hydroarylation of gem‐difluoroalkenes under mild conditions with the aid of Ni─H intermediate catalysis, which is capable of efficiently synthesizing compounds containing the structural motifs and possesses good functional group tolerance.

Bright and Versatile Azetidinecarboxamide‐Based Fluorophore–Ligand Conjugates for High‐Resolution Cell Imaging

AbstractFluorophore–ligand conjugates play a pivotal role in cellular imaging, providing high target specificity. However, simultaneously achieving conjugates with high brightness and ligand‐targeting diversity presents significant challenges. Traditional strategies often require complex, multistep modifications for fluorophore enhancement and ligand conjugation. Here, we present an azetidinecarboxamide strategy that addresses these challenges by integrating brightness enhancement and ligand conjugation capabilities within a single molecular framework. The azetidinecarboxamide core suppresses twisted intramolecular charge transfer (TICT), thereby enhancing fluorescence quantum yield. Its carbonyl group provides a versatile site for conjugating a wide range of targeting ligands, enabling the rapid development of diverse and tunable fluorophore–ligand conjugates. This streamlined approach reduces synthetic complexity, accelerates probe development, and is compatible with a wide variety of fluorophores, such as coumarin, naphthalimide, NBD, rhodol, rhodamine, and silicon–rhodamine, facilitating the creation of high‐performance, multifunctional probes for advanced cellular imaging.

Pressure‐Induced Emission Luminogens Enable Optical Logic Gates Toward Lighting, Scintillators, and Anti‐Counterfeiting

AbstractThe pressure‐induced emission luminogens (PIEgens) opened the door to highly emissive materials. However, the high‐pressure phase with excellent optoelectrical properties is difficult to stabilize at ambient conditions, seriously limiting the practical applications. Here, we first lighted up non‐emissive zero‐dimensional (0D) metal halide (C25H22P)2SnCl6 via pressure engineering, ultimately yielding the bright emission. Note that the quenched (C25H22P)2SnCl6 after pressure treatment of 20.0 GPa exhibited very bright blue–white emission. This irreversible photoluminescence (PL) transition was associated with irreversible amorphization by increasing the potential barrier of phase transition through the steric hindrance effect. The increased distortion of inorganic octahedra and the enhanced hydrogen bond interaction within the amorphous (C25H22P)2SnCl6 after pressure treatment were responsible for the bright emission. Thus, pressure‐triggered PL turn‐on behavior can serve as a robust optical switchable logic gate from the initially dark state “0” to the bright state “1”. Furthermore, the pressure‐treated (C25H22P)2SnCl6 exhibited an unexpected excitation‐dependent emission. The unique characteristic of “PIE” with different colors can be decoded the Morse code encrypted with the pressure‐treated (C25H22P)2SnCl6 and different excitations. The quenched (C25H22P)2SnCl6‐based phosphor‐converted light‐emitting diodes (pc‐LEDs), X‐ray dose rate detection and centimeter‐level patterns highlighted great potentials in lighting, display, scintillators, and anti‐counterfeiting.

Solid‐State Photoconversion of a Discrete Mixed Iodine(I) System to a 1D Polymer

AbstractThe first example of a mixed halogen(I) complex (2), containing three distinct iodine(I) moieties ([N―I―N]+, O―I―N, and [O―I―O]−) within the same structure, was synthesized with 4‐styrylpyridine (4‐stypy) and 3,4,5,6‐tetrafluorophthalate as the stabilizing Lewis bases. This complex was observed to be in equilibrium with its respective bis(OIN) complex (1a), with isolated samples of 2 also being found to convert to 1a in solution. Upon UV irradiation of 2, a single‐crystal‐to‐single‐crystal [2 + 2] cycloaddition reaction was observed, converting the discrete salt 2 to the 1D polymer 5. Complex 5 retained all the iodine(I) moieties from prior to photoconversion and represents the first example of nondestructive photoconversion of a halogen(I) complex. To facilitate comparisons to 2 and 5, several additional closely related iodine(I) complexes were synthesized, with the iodine(I) complexes characterized by NMR (1H, 1H‐15N HMBC) and SCXRD, as well as by Raman and IR spectroscopy for 2, 5, and their close structural analogue 1a.

Dynamic Borate Esterification for Evolved Supramolecular Chirality and Chiral Optics

AbstractTopological chemical reactions in confined environments offer unique opportunities for constructing dynamically tunable crystalline materials and architecturally defined polymers. However, their potential within functional supramolecular systems and chiral materials remains largely untapped. In this work, we introduce, for the first time, a borate esterification reaction to achieve dynamic modulation of supramolecular chirality and chiroptical properties under aggregation conditions. Pyrene‐phenylalanine derivatives, following functionalization with phenylboronic acid groups, coassemble with catechol‐functionalized pyrene derivatives. This coassembly undergoes spontaneous and highly efficient borate esterification under ambient conditions, inducing nanoscale morphological evolution, and an inversion of supramolecular chirality. Both experimental results and DFT‐based computations reveal that the supramolecular chirality inversion is primarily driven by a transition from π–π stacking to CH–π interactions between pyrene moieties. This coassembly‐borate esterification process represents a powerful integration of noncovalent assembly and covalent chemistry, providing a versatile platform for the design of soft materials and chiral functional systems. Moreover, the introduction of alizarin derivatives containing catechol motifs enables the transfer of circularly polarized luminescence (CPL), resulting in tunable emission shifts from blue and cyan to red. This work broadens the functional scope of chiral luminescent materials and opens new avenues for their application.

Modulating the Chromophores of Metal‐Covalent Organic Frameworks for Boosting Low‐Concentration CO₂ Photoreduction

AbstractThe development of efficient photocatalysts to convert low‐concentration CO2 into the value‐added chemicals and fuels is particularly interesting yet remains highly challenging. Herein, we designed and synthesized three metal‐covalent organic frameworks (MCOFs) through the Schiff‐base condensation reactions between trinuclear copper complex and different BDP‐based chromophores (BDP = 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene) for visible‐light‐driven reduction of low‐concentration CO2 (15%) to HCOO−. As a result, MCOF‐ANT containing anthracene (ANT) groups achieves the highest HCOO− production rate of 1658 µmol g−1 h−1 (HCOO− selectivity, ∼100%) in the absence of any additional noble‐metal photosensitizers under a laboratory light source, which is 7.2 and 2.1 times higher than those of MCOF‐Ph and MCOF‐Nap with phenyl (Ph) and naphthalene (Nap) groups, respectively. Furthermore, MCOF‐ANT also exhibits excellent photocatalytic activity for the reduction of low‐concentration CO2 (15%) to HCOO− under natural sunlight, with a HCOO− production rate of 1239 µmol g−1 h−1 (HCOO− selectivity, ∼100%). Experiments and theoretical calculations reveal that the presence of ANT in MCOF‐ANT is favorable to the visible‐light harvesting and charge separation, as well as the formation of *OCO intermediate, which clearly accounts for its superior catalytic activity.

Monitoring Glycolysis by Endogenous ³¹P CEST Magnetic Resonance Imaging

AbstractIn this study, we present a novel approach to investigate glycolysis by means of the 3¹P CEST technique applied to phosphate‐containing substrates at their endogenous concentration. The method relies on the assessment of the saturation transfer (ST) observed on the 3¹P signals of inorganic phosphate (Pi) or phosphocreatine (PCr) following the selective irradiation of phosphate groups of endogenous molecules exchanging with ATP, Pi, and indirectly with PCr in enzyme‐catalyzed reactions. The concentrations of these substrates often fall below the threshold for direct detection. The 3¹P CEST technique amplifies their responses, making them detectable via the ST effect to the 3¹P resonance of the selected reference signal. The method was first validated in vitro on mouse breast adenocarcinoma cell pellets (TS/A), where the intracellular Pi signal was monitored to assess the ST effect associated with the saturation of phosphoester‐containing molecules. The use of a glycolysis inhibitor and different experimental temperatures (37 °C or 4 °C) provided insights supporting the rationale behind the method. A comparison of 3¹P Z‐spectra was carried out on murine breast cancer cell lines with different degrees of aggressiveness, showing the ability to assess metabolic differences. Finally, in vivo experiments on mice models of mammary adenocarcinoma demonstrated that 3¹P CEST can differentiate tumor and healthy tissue based on their metabolic characteristics.

A Nucleus‐Targeting Ruthenium(II) Complex Induces DNA Condensation in Cisplatin‐Resistant Tumor Cells

AbstractOne of the conventional ways to eradicate tumor cells is to utilize chemotherapy agents, e.g., cisplatin, to induce DNA damage. However, DNA damage repair mechanisms can significantly limit the therapeutic efficacy of cisplatin. These mechanisms enable tumor cells to repair the DNA damage caused by the drug, leading to resistance. Cisplatin and similar drugs bind to specific DNA sites without significantly altering their conformation. As a result, DNA repair enzymes can still attach to and repair the damaged DNA. To address this issue, we designed four Ru(II) complexes (RuC3, RuC6, RuC9, and RuC12) with high positive charges of +8 valence and regulated their nuclear accumulation levels by adjusting the length of alkyl chains. RuC9 exhibits the highest nucleus accumulation level. DNA conformation was significantly altered by inducing DNA condensation through indiscriminately neutralizing the negative charge of the DNA backbone. This significant change prevents DNA‐related enzymes from binding to DNA, ultimately leading to the efficient eradication of various tumor cell lines. To the best of our knowledge, it is the first work that kills tumor cells and overcomes cisplatin resistance through inducing DNA condensation.