Chemical Reviews最新文献

The structures, bonding, energetics, preparation, characterization, and reactions, both stoichiometric and catalytic, are categorized for all paramagnetic hydride complexes (PHC) with terminal hydrides and then bridging hydrides: 58 and 177 crystallographically characterized, respectively, including 49 mixed-valence complexes. Common methods of synthesis are documented and trends in PHC properties are revealed. The tabulated experimentally and theoretical bond energies indicate that PHC with similar ligands have weaker M-H bonds than diamagnetic hydrides. Magnetometry- and EPR-related results are tabulated and interpreted in terms of the bonding. Most complexes with bridging hydrides have reduced magnetic moments due to antiferromagnetic coupling. Hyperfine coupling constants range from small for the Ni^III-H-Fe^II Ni_aC state of [NiFe] and the Fe-H-Fe E₄(4H) state of [MoFe] nitrogenase to 293 MHz (for matrix-isolated NH(CO)₃₎ depending on the orbitals involved in bonding and the Fermi contact term. Hydride ¹H NMR resonances were detected for ten compounds with populated paramagnetic states. Reactions featured include oxidation, proton loss, hydrogen atom transfer, hydrogen loss and substitution, hydride transfer and reduction. Brief details of more than 40 homogeneous catalytic processes involving suspected PHC are provided. Since PHC are mainly found for earth-abundant 3d metals, there continues to be much interest in their properties and uses in sustainable catalysis.

Nanopipette electrochemistry has emerged as a versatile platform for nanoscale analytical measurements, functional device fabrication, and biomimetic interface construction. The confined geometry at the nanopipette orifice can be a powerful tool for ultrasensitive measurement through analyzing the ionic current across the nanopore. Chemists can rationally engineer the surface properties of nanopipettes by modifying the glass orifice through physical deposition or chemical reactions, enabling dynamic tuning of ion transport based on the interaction between the analyte and the interface. Such interfacial modulation governs the ionic flux and provides insights into local molecular processes. We first discuss ion current rectification (ICR) sensing, which enables surface-state probing via asymmetric ionic flux. Facilitated by the development of low-noise, high-bandwidth instruments, label-free and high-throughput detection and characterization of nanoparticles, single molecules, and real-time biological interactions could be achieved through resistive-pulse sensing. Furthermore, we highlight the role of wireless nanopore electrodes (WNEs) in studying electron transfer processes at the single-entity level, including redox processes in molecules, nanomaterials, and cellular metabolism. Nanopipettes also offer precise spatial control for the bottom-up electrochemical construction of functional nanostructures. Looking ahead, the integration of nanopipette arrays, hybrid analytical techniques, and adaptive interfaces and nanopipette electrochemistry is expected to enable the development of intelligent ionic circuits, neuromorphic systems, and next-generation molecular-scale computing platforms.

Conducting polymers, particularly those capable of transporting both ionic and electronic charges─commonly referred to as organic mixed ionic-electronic conductors (OMIECs)─have played a transformative role in enabling bidirectional communication between biological systems and electronic circuits. This ability has driven the field of bioelectronics to expand in three distinct directions: biointerfacing, sensing, and neuromorphic computing. Biointerfacing and sensing allow for the extraction of interpretable chemical and electrochemical signals from living organisms, while neuromorphic computing, in addition to efficiently processing complex signals, can translate electronic signals into the frequency domain that the nervous system uses to communicate. In the bioelectronics context, OMIECs have been untethered from previous requirements of high charge mobility, fast switching times, and long-range crystallinity, which makes electropolymerization a more attractive route to fabricate OMIECs on bioelectronic devices. This review examines the fundamental principles, practical aspects, and prominent applications of OMIEC materials fabricated by electropolymerization.

As lithium-ion batteries approach their theoretical capacity limits, lithium metal batteries (LMBs) have emerged as promising candidates for next-generation energy storage, offering substantially higher energy densities. However, their practical deployment remains limited by several interrelated challenges including lithium dendrite growth, parasitic side reactions, unstable solid electrolyte interphases (SEI), and poor cycling stability. While recent advances in electrolyte design, anode architecture, and interfacial engineering have significantly improved electrochemical performance, the thermal stability and safety of LMBs, particularly at the interface and electrode levels, still require extensive investigation. This review provides a comprehensive mechanistic analysis of thermal instability in LMBs, spanning material degradation, interfacial decomposition, and cell-level thermal behavior. We critically examine the roles of lithium metal, liquid- and solid-state electrolytes, and diverse cathode chemistries (e.g., layered oxides, sulfur) in triggering exothermic reaction pathways, gas evolution, and thermal runaway. The complex coupling among electrode–electrolyte interactions, interphase chemistry, electrochemo-mechanics, morphological evolution, and thermal instability across emerging LMB chemistries is highlighted. By identifying dominant thermal instability mechanisms and key knowledge gaps, this review establishes a mechanistic foundation for designing thermally resilient LMBs and outlines future directions for advancing safety in high-energy battery systems.

A material tears, peels, and breaks by growing a crack. In a zone around the crack front, atoms undergo an irreversible process of breaking─and possibly reforming─bonds. Trailing behind the crack front are two layers of scars. Outside the irreversible zone and scars, atoms undergo the reversible process of elasticity. The irreversible zone is considered localized if it is small relative to the body. The idealization of localized irreversibility leads to a thermodynamic framework centered on the energy release rate. This crack driving force is defined using an ideal body in which a crack is stationary and deformation is elastic, and is applied to a real body in which a crack grows by an irreversible process. The irreversible zone scales with a material length: the fractocohesive length. We review recent advances in the development of crack-resistant elastomers and hydrogels as well as polymer networks reinforced by hard particles, fibers, or fabrics, subject to monotonic, cyclic, and static loading. Emphasis is placed on how molecular features, such as strand length, entanglements, noncovalent bonds, and chemical reactions, govern crack resistance. Design principles are highlighted that reconcile high toughness with low hysteresis through stress deconcentration. This review traces crack resistance to molecular origins, providing a foundation for designing next-generation crack-resistant materials.

This extensive review highlights the central role of classical molecular simulation in advancing hydrogen (H₂) technologies. As the transition to a sustainable energy landscape is urgently needed, the optimization of H₂ processes, spanning production, purification, transportation, storage, safety, and utilization is essential. To this end, accurate prediction of thermodynamic, transport, structural, and interfacial properties is important for overcoming engineering challenges across the entire H₂ value chain. Experimental measurements, despite being the traditional way of obtaining these properties, can be limited by the distinctive nature of H₂, harsh operating conditions, safety constraints, and extensive parameter spaces. Free from such limitations, classical molecular simulations, in the general frameworks of Monte Carlo and Molecular Dynamics, provide an optimal balance between computational efficiency and accuracy, bridging the gap between quantum mechanical calculations and macro-scale modeling. This review also systematically covers molecular simulation methods and force fields for computing key properties of H₂ systems, such as phase and adsorption equilibria and transport coefficients. Beyond property prediction, we explore how molecular simulation reveals fundamental mechanisms governing hydrate formation and dissociation, membrane permeations, and H₂ embrittlement. When possible, data from multiple sources are compared and critically assessed, while effort is put on evaluating the force fields used and methodological approaches followed in the literature. Finally, this review aims at identifying research gaps and future opportunities, emphasizing emerging approaches, such as molecular simulation in the era of artificial intelligence.

Ionogels, an emerging branch of gels, are polymer networks swollen with ionic liquids. Ionogels are nonvolatile and possess ionic conductivity as well as high thermal and electrochemical stability. These fascinating features make ionogels extremely attractive in many fields, such as wearable and flexible electronics, energy storage devices, and sensors. Yet, ionogels usually suffer from poor mechanical properties, which severely limits their applications. To solve this problem, a lot of effort has been devoted to improving ionogels. Here, we present a review mainly focusing on the toughening mechanisms of ionogels, given the critical role of mechanical behaviors in their applications. Meanwhile, the physicochemical properties, synthetic strategies, patterning methods, and applications of ionogels are considered. We hope this review will not only inspire further research but also provide guidance for the rational design of tough ionogels, thereby broadening their potential.

Lignocellulosic films (LCFs) have garnered significant attention due to their unique combination of flexibility, functionality, cost-effectiveness, and eco-friendliness. Defined as thin, compact, and continuous sheets with a typical thickness in the range of 10–100 μm, LCFs have been used in various fields, including packaging, flexible electronics, energy storage and harvesting, sensing, water treatment, and agriculture. Based on preparation strategies and chemical compositions, LCFs can be categorized into cellulose derivative films, regenerated cellulose films, nanocellulose films, hemicellulose films, lignin-based films, and whole lignocellulosic biomass films. While previous reviews often focus on specific types of LCFs, e.g., nanocellulose films, a comprehensive review covering all categories and their recent advancements is still lacking. This review aims to address this gap by providing a thorough overview of the basic structure and chemistry of lignocellulosic biomass, preparation strategies, functionalization methods, and the broad spectrum of applications of LCFs. Additionally, it examines the environmental and economic feasibility of LCFs and identifies strategies to overcome existing challenges, offering valuable insights for advancing the field and supporting future innovation in sustainable material science.

Colloidal particles emerge as promising building blocks for the construction of novel materials and devices owing to their tailorable morphologies, abundant species, and intriguing properties. In comparison to other assembly approaches, optical colloidal assembly relies on photophysical or photochemical interactions and allows the arrangement of particles into desired geometries on a substrate with high spatial and temporal resolution. Typically, optical colloidal assembly involves two major processes, i.e., optical manipulation for colloidal arrangement and light-triggered interparticle bonding for colloidal immobilization. In this review, we first categorize the optical manipulation techniques based on different working principles and discuss their technical features and assembly capabilities. We then provide a comprehensive overview of different colloidal bonding schemes, including van der Waals attraction, dipole–dipole interaction, biochemical linking, photopolymerization, and surface ligand bonding. Finally, we summarize the cutting-edge applications of assembled colloidal structures and end with our vision for the existing challenges and future development in this field.