Cationic chromophores like cyanines and xantheniums are prevalent fluorescent dyes used for imaging and as probes. In non-polar environments, however, electrostatic interactions drive formation of ion pairs with the accompanying...
The rational discovery of new RTP emitters remains challenging because phosphorescence depends on multiple competing processes, including intersystem crossing, nonradiative decay, and competition with fluorescence. While several mechanistic hypotheses have...
MnO2 cathodes would undergo one-electron or two-electron transfer reactions in aqueous zinc batteries, with the latter providing doubled theoretical capacity. However, with the proton as one of the reactants for the two-electron reduction, its contribution is limited in typical mildly acidic zinc batteries. The long-term stability is further hindered by irreversible material loss. Herein, we incorporate a surfactant of sodium dodecyl benzene sulfonate (SDBS) into MnO2 to regulate its reaction preference. SDBS not only prevents MnO2 nucleus aggregation but also enhances electrostatic attractions for cations in the system. The resulting proton adsorption facilitates the two-electron dissolution reaction during discharge, and this is further promoted by the weaker Mn binding in the lattice after SDBS interaction. Meanwhile, the attraction of Mn2+ together with homogenized flux enables its reversible back-deposition following the three-dimensional instantaneous nucleation model during charge. As a result, the MnO2/SDBS cathode delivers 446 mAh g-1 high capacity at 0.1 A g-1 and realizes 84% capacity retention over 10 000 cycles at 2 A g-1 in the ZnSO4 electrolyte without pre-added Mn2+. It also achieves over 2.5 mAh cm-2 capacity with 10 mg cm-2 high loading. The strategy is further validated with another surfactant containing the featured negatively charged head and alkyl tail.
All solid-state sodium batteries (ASSSBs) are promising for safe, low cost, and large-scale energy storage, but further development is limited by the difficulty of identifying an inorganic solid electrolyte (SE)...
Multivalent cations are abundant in cells and play essential roles in DNA duplex stability, genome packaging, and DNA-protein interactions. They can also condense DNA, making it challenging to determine their influence on DNA duplex stability. To overcome this challenge, we studied DNA unpeeling at equilibrium under high tension using magnetic tweezers, thereby preventing condensation. Experiments show that DNA duplex stability first increases and then decreases as cation concentration increases and the maximum DNA duplex stability increases with cation valence. The maximum free energy change of DNA was 3.33 k B T/bp for Na+ and increased to 3.98 k B T/bp for protamine, which is a small arginine-rich protein with a highly positive charge (≈21 for salmon sperm), corresponding to a relative increase of 19.5%. Consistently, all-atom molecular dynamics simulations show that higher-valent cations preferentially embed in the minor groove of DNA and clamp the minor groove, in contrast to the major-groove clamping reported for RNA, thereby stabilizing the helix more efficiently. These findings establish a single-molecule framework for quantifying DNA thermodynamics in complex ionic environments, which contributes to understanding ionic control of genome stability and to designing ion-tunable DNA-based nanostructures and delivery systems.
Transition-metal spinels hold immense promise for the oxygen evolution reaction (OER), yet their inherently strong metal-oxygen bonds severely restrict the activation of lattice oxygen, locking the reaction into the kinetically sluggish adsorbate evolution mechanism (AEM). Herein, we propose a metal-oxygen covalency engineering strategy to modulate the octahedral sites of NiCo2O4 spinel by modifying the tailored Ru and Fe bimetallic ions. The preferential incorporation of high-valent Ru significantly enhances M-O bond covalency and upshifts the O 2p band center, lowering the thermodynamic barrier for the lattice oxygen mechanism (LOM) pathway. Concurrently, the synergistic Fe species functions as an electronic buffer that effectively suppresses metal dissolution and stabilizes the lattice framework, thereby preventing structural collapse. Impressively, the optimal RuFe-NiCo2O4 catalyst bypasses the inherent AEM scaling relationships, delivers an exceptionally low overpotential of 390 mV at 500 mA cm-2 and retains excellent catalytic stability for 800 h in a prototype anion exchange membrane water electrolyzer (AEMWE). This work establishes a highly rational and feasible route for the design of next-generation, industrial-grade water splitting electrocatalysts.
Tin halide perovskite solar cells are considered one of the most promising alternatives to conventional lead-based perovskite photovoltaics due to their structural and electronic similarities, along with their lower toxicity. However, the chemistry of tin halide perovskites is distinct from that of their lead counterparts. As a result, tin halide perovskite solar cells still lag behind lead-based devices in both performance and long-term stability. This review summarizes recent progress in strategies to address these challenges, focusing on controlling key issues such as Sn2+ oxidation, rapid crystallization, and high defect densities. Specific approaches discussed include precursor purification, the use of chemical additives, compositional engineering, surface modifications, interlayers, and the design of charge-transporting materials. Future advances will require the development of thicker high-quality absorber layers, robust electron- and hole-selective contacts, improved operational durability, and scalable fabrication methods. These integrated strategies will be essential for realizing efficient, stable, and large-area lead-free perovskite photovoltaics.
Radical-radical reactions of resonantly stabilized species such as propargyl (C3H3˙) and benzyl (C7H7˙) efficiently generate polycyclic aromatic hydrocarbons (PAHs). Key mechanisms-propargyl addition-benzannulation (PABA), methyl addition-ring expansion (MARE), and cyclopentadienyl addition-naphthylization (CPAN)-govern early-stage aromatic growth, but transforming these mechanisms to larger PAHs is computationally challenging due to combinatorial intermediates and reactions on excited state triplet surfaces. Here, we introduce a "periodic system" of PAHs that organizes aromatic growth according to transferable radical-radical motifs, enabling prediction of molecular evolution across the size regime. Using (2-naphthyl)-methyl (2-C11H9˙) and benzyl (C7H7˙) radicals as benchmarks, we experimentally demonstrate the predicted gas-phase formation of four- and five-ring PAHs, including (1) C18H12 isomers: tetracene, benz[a]anthracene, and [4]helicene; (2) C22H14 isomers: benzo[a]tetracene, benzo[a]tetraphene, and [5]helicene. Secondary hydrogen-loss and successive reactions produce even larger 2D and 3D aromatics, such as nanobowls and fullerenes, and their building blocks (corannulene and coronene). This framework provides a unifying and predictive description of PAH growth across combustion and circumstellar environments such as carbon-rich envelopes of late-type Asymptotic Giant Branch (AGB) stars and planetary nebulae.
Aqueous Sn-air batteries offer the advantages of low cost, high safety, and high theoretical capacity. However, Sn anodes are susceptible to the hydrogen evolution reaction (HER) and "dead Sn" detachment, leading to reversible capacity decay and severely limiting battery performance. Herein, we propose a DPP2-HHTP-COF mediated electron-ion decoupling strategy. An artificial electronically conductive DPP2-HHTP-COF interfacial layer is constructed on the Sn anode. The DPP2-HHTP-COF conjugated framework and electron-accepting units synergistically reconstruct the interfacial electronic structure, forming an electron-deficient layer and increasing the HER energy barrier. Meanwhile, the active coordination sites of the DPP2-HHTP-COF interfacial layer enable selective binding of SnO2 2-, constructing dedicated ion-transport channels, optimizing Sn deposition/dissolution kinetics, and suppressing "dead Sn" formation. Consequently, interfacial stability is significantly enhanced. The assembled Sn-air battery with the DPP2-HHTP-COF@Sn anode achieves an ultra-long cycle life of 15 000 h (625 days) at 0.1 mA cm-2, delivers 5291 stable cycles at 2 mA cm-2/0.3 mAh cm-2 with a coulombic efficiency approaching 100%, and maintains stable operation for ∼1150 h even at 60 °C. This work provides a molecular-level strategy for interfacial modification of Sn anodes and offers valuable insights for the development of high-performance aqueous Sn-based batteries.
Electroreduction of carbonate and bicarbonate is emerging as a chemically distinct route beyond conventional gas-fed CO2 electrolysis. Yet the nominal ionic-carbon feed does not uniquely identify the immediate electroactive species. This review examines both indirect conversion, in which HCO3 - or CO3 2- is locally protonated to regenerate molecular CO2 before conventional CO2RR, and direct conversion, in which solvated (bi)carbonate-derived species are activated at the cathode. We further discuss a surface- or lattice-mediated regime involving catalyst-bound carbonate reservoirs. Although these pathways may coexist, they differ fundamentally in carbon-species transport, interfacial reaction steps, catalyst-design requirements and reactor architectures. Using this pathway-resolved framework, we analyze the roles of acid-base speciation, proton-coupled electron transfer, cation-carbonate structuring, membrane-regulated carbon flux and catalytic microenvironments. We further evaluate catalyst and electrolyzer design, mechanistic evidence, carbon accounting and integration with carbon capture, including emerging direct-air-to-chemicals concepts. Finally, we identify the mechanistic and system-level requirements for advancing (bi)carbonate electrolysis towards energy-efficient, closed-loop capture-conversion processes.
Small-molecule based sonosensitizers hold great promise for deep-seated tumor therapy, yet their structure-activity relationships (SARs) remained largely unexplored, hindering their further biomedical applications. Herein, we propose a counterion-engineering strategy to modulate the aggregation behaviour of aza-BODIPY dyes, thereby achieving high-performance sonodynamic therapy (SDT). We demonstrated that Cl--paired aza-BODIPY dye (BT-Cl) formed nanoparticles with the smallest hydrodynamic diameter and yielded the highest levels of reactive oxygen species (ROS). BT-Cl NPs also displayed potent sonodynamic cytotoxicity toward both 4T1 and U87-MG cells. Consequently, BT-Cl exhibited excellent tumor growth inhibition with minimal side effects. Overall, this work underscored the critical role of noncovalent ion-pairing interactions in governing small-molecule sonosensitizer aggregation and provided a facile approach for the rational design of high-efficiency sonosensitizers.
Optically active epibromohydrins represent a structurally privileged family of chiral building blocks, yet their asymmetric synthesis remains hampered by a reliance on stoichiometric chemical oxidants and multi-step protocols. Herein, we report an organocatalytic asymmetric electrochemical bromoetherification of allylic tertiary alcohols that constructs these densely functionalized scaffolds in a single operational step. By merging interfacial electrosynthesis with a synergistic chiral phase-transfer catalyst (PTC) and chiral phosphoric acid (CPA) counter anion framework, the high reactivity of electrogenerated Br2 species is tightly regulated, successfully suppressing unselective, racemic background pathways. Utilizing inexpensive NaBr as the bromine source in a DCM/H2O biphasic system, a range of allylic tertiary alcohols were smoothly converted into the corresponding bromoepoxides in high yields and with high enantioselectivities. Control experiments and cyclic voltammetry studies suggested that stereocontrol is sensitive to the balance between anodic bromide generation and phase-transfer-mediated trapping. This strategy is complementary to the conventional synthesis of epibromohydrins by chemical oxidation.
The hydrogen evolution reaction (HER) is central to green hydrogen production, yet its sluggish kinetics impose a fundamental limit on energy conversion efficiency. Catalyst design is undergoing a paradigm shift from static optimization toward dynamic control, as the catalytically active phase often emerges in situ at reductive potentials, giving rise to the concept of the "pre-catalyst". While oxidative reconstruction in the oxygen evolution reaction (OER) has been extensively studied, pre-catalyst reductive reconstruction under HER conditions involves metal-hydrogen (M-H) chemistry and remains mechanistically elusive. This review presents a "dynamic reconstruction to rational design" framework for HER pre-catalysts, surveying reconstruction pathways, dissecting extrinsic-intrinsic driving forces (potential, pH vs. electronic structure, and defects), and distilling strategies (defect engineering, chemical state modulation, etc.) that pre-encode the target active phase. We further highlight the methodological synergy of multimodal operando characterization and multiscale computation and argue that HER reconstruction is a thermodynamically driven, chemically pre-programmable evolutionary process rather than an incidental phenomenon. This reconstruction-centered view offers a design logic that extends beyond the HER to other reductive electrocatalytic systems.
Chemically induced proximity of biomacromolecules is a powerful strategy to regulate cellular processes using small molecule ligands that act as “molecular glues” to influence complex lifetime, localization and function. However,...
Macrocyclic peptides possess numerous advantages, including enhanced tissue penetration, low immunogenicity, good resistance to protease degradation, and high targeting specificity, making them increasingly attractive for drug development. Genetically encoded cyclic...
The practical application of aqueous zinc-ion batteries (AZIBs) is severely hindered by the poor reversibility of Zn anode, which stems from a self-amplifying cycle involving dendrite growth, interfacial side reactions,...
The protection of N ̶ H groups is often essential to harness highly valuable metal-catalyzed C ̶ C coupling protocols. However, the avoidance of protecting groups has enormous advantages in...
The complex absorbing potential (CAP) method is an effective approach to model anionic resonances. However, the existing optimization criteria for the CAP strength give rise to multiple solutions, and the...
