Accounts of Chemical Research最新文献

{"title":"Molecular Ring Remodeling through C-C Bond Cleavage.","authors":"Zengrui Cheng, Zhibin Hu, Ning Jiao","doi":"10.1021/acs.accounts.4c00846","DOIUrl":"10.1021/acs.accounts.4c00846","url":null,"abstract":"<p><p>ConspectusStable and inert C-C bonds form the fundamental framework of organic compounds. Consequently, direct transformations involving C-C bond cleavage present an innovative approach for the rapid modification and remodeling of molecular skeletons. In recent years, the concept of molecular skeletal editing has garnered widespread attention and has been significantly developed, providing new opportunities for the late-stage modification of bioactive molecules, the high-value transformation of bulk chemicals, and a revolution in the traditional fragment coupling strategies of chemical synthesis. Notable advancements in this field have focused on C-C bond cleavage and the remodeling of cyclic molecules, including ring expansion, ring contraction, and ring-opening reactions, thereby enriching the synthetic toolbox available to chemists. However, selective C-C bond transformation remains a formidable challenge, especially in the remodeling of complex molecules, due to the high bond dissociation energy and the difficulty in achieving precise selectivity control. Over the past few years, our group has made efforts to address these challenges. We have demonstrated the potential of cyclic molecule remodeling reactions as an efficient strategy for the synthesis and modification of complex molecules.Herein, we present two major thematic advancements achieved by our group, utilizing cascade activation and entropy-driven reconstruction strategies for molecular ring remodeling via C-C bond cleavage. These strategies are characterized by mild conditions, the accessibility of catalysts and reagents, and exceptional functional group compatibility, thereby emerging as novel approaches for molecular ring remodeling through atom-incorporation reactions mainly on nitrogenation, oxygenation, and halogenation to synthesize pharmaceuticals, natural products, and material molecules. (1) Ring expansion reactions: We developed novel reactions that enable the insertion of C-, N-, and O-containing units into molecular rings. These methodologies offer practical and efficient routes for synthesizing amides, amines, lactones, and nitrogen-containing heterocycles. (2) Ring-opening reactions: C-C bond cleavage in ring-opening reactions enables the efficient construction of distally difunctionalized molecular frameworks. By utilizing a transition metal catalysis and radical-mediated process, we have successfully achieved the cleavage of both C-C single bonds and C═C double bonds within molecular rings. Furthermore, we have tackled the highly challenging arene ring-opening (ARO) reaction, enabling the construction of stereoselective conjugated systems through the unsaturation liberation of aromatic systems. Mechanistic studies and DFT calculations have provided critical insights into these processes. We have also identified key intermediates involved in C-C bond cleavage, including benzyl azide, <i>O</i>-acetyl hydroxylamine, β-azido peroxyl radical, copper bisnitrene, and","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"1003-1022"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N-Atom Deletion Involving Rearrangement of Sulfamoyl Azides or Triazanium Salts.","authors":"Bowei Huang, Hongjian Lu","doi":"10.1021/acs.accounts.4c00853","DOIUrl":"10.1021/acs.accounts.4c00853","url":null,"abstract":"<p><p>ConspectusAmines are frequent structural components in natural products, pharmaceuticals, ligands, and catalysts, making their synthesis and transformation essential to organic chemistry. While C-N bond formation has become a well-established and reliable synthetic strategy, the selective cleavage of C-N bonds remains relatively underexplored. This challenge arises from the low heterolytic nucleofugality of nitrogen, a property that limits the practical application of C-N bond cleavage. This gap underscores a significant area in synthetic methodology in need of further development. In this context, N atom deletion─defined as the selective removal of a nitrogen atom <i>via</i> C-N bond cleavage, while preserving the integrity of the remaining framework─has emerged as a promising approach for skeletal editing. Since Levin's landmark 2021 report, N atom deletion has gained attention for its potential to precisely modify molecular skeletons. Building on the skeletal editing concepts advanced by Levin and Sarpong, particularly their strategies for modifying cyclic frameworks, we recognized the critical need for developing mild and efficient methods that enable the structural manipulation of cyclic systems.This Account summarizes our research since 2017, focusing on two approaches to N atom deletion with distinct mechanisms: the rearrangement of sulfamoyl azides and the conversion of triazanium intermediates. Initially, we explored and optimized the thermal rearrangement of sulfamoyl azides derived from secondary amines, discovering its potential as a viable synthetic strategy for N atom deletion. In 2024, we introduced an O-diphenylphosphinyl hydroxylamine (DPPH)-promoted N atom deletion, involving the generation and novel rearrangement of triazanium intermediates. Both methods enable the conversion of polar aliphatic amines into nonpolar scaffolds and are applicable to both linear molecules and cyclic systems of varying sizes. The DPPH-based approach, in particular, demonstrated exceptional effectiveness for sterically hindered substrates with mild reaction conditions and no need for anhydrous or oxygen-free environments. The mechanisms of two methods─both via isodiazene and radical intermediates─were elucidated through rigorous experimental investigation. Additionally, we observed the rapid formation of hydro(deutero)deamination products when primary amines were exposed to DPPH.Beyond its role as a typical skeletal editing strategy, N atom deletion of secondary amines has emerged as a crucial synthetic approach. Though with limitations, it transforms the challenging task of constructing C-C bonds into a more manageable sequence: the formation of C-N bonds following selective N atom removal. We have applied this strategy in the synthesis of natural products, ligands, hydrocarbon cages, and pharmaceuticals. We hope that this work will stimulate further interest in N atom deletion as a skeletal editing strategy and encourage its incorporation int","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"919-932"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical Strategies to Modulate and Manipulate RNA Epigenetic Modifications.","authors":"Liang Cheng","doi":"10.1021/acs.accounts.4c00844","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00844","url":null,"abstract":"<p><p>ConspectusRNA epigenetics has rapidly emerged as a key frontier in chemical biology, revealing that modifications to RNA bases and riboses can fine-tune essential cellular processes such as gene expression, translation, and metabolic homeostasis. Traditionally, researchers have relied on manipulating the \"writers,\" \"erasers,\" and \"readers\" of RNA modifications─<i>i.e.</i>, protein cofactors─to alter and study these marks. Those enzyme-centric strategies, including small molecule inhibitors and CRISPR/Cas-based genetic perturbations, have been highly effective and are advancing in clinical applications. However, purely chemical approaches for installing, removing, or transforming RNA modifications without enzyme disturbance have offered distinct advantages, such as temporal control, reversibility, and bypassing compensatory biological feedback mechanisms that often arise with genetic or enzymatic inhibition. Every chemist should be concerned about RNA modifications, because they represent a striking intersection of molecular recognition, organic transformation, and cellular function. The ability to direct chemical reactivity at specific nucleosides in RNA can illuminate how individual modifications impact the overall gene regulation. Further, since improper RNA modification and damage patterns are implicated in cancer, metabolic disorders, and neurodegeneration, these chemical repair tools have potential as diagnostic and therapeutic interventions. Beyond medicine, agriculture also stands to benefit from chemical control of nucleoside-based plant hormones, possibly leading to improved crop productivity and resilience.In this <i>Account</i>, we outline several innovative chemical strategies tailored to different classes of RNA modifications. Flavin-based bioorthogonal chemistry has enabled demethylation of <i>N</i><sup>6</sup>-methyladenosine (m<sup>6</sup>A) independent of endogenous demethylases, while oxidative bioorthogonal reactions can convert 5-methylcytidine (m<sup>5</sup>C) into distinct formyl derivatives for labeling and sequencing. Nitrogen-oxide and photochemical routes provided access for the selective removal of the side chain of <i>N</i><sup>6</sup>-isopentenyladenosine (i<sup>6</sup>A), offering insights for both cell biology and plant hormone research. We also showcase how rationally designed small molecules can rewire complex RNA damage repair pathways, facilitating selective correction of vinyl-adduct lesions otherwise resistant to enzymatic repair. These purely chemical methods bypass the constraints of enzyme dependence, affording temporal precision (e.g., <i>via</i> light activation) and site-selective modification or labeling of RNA. By strategically engineering reactivity, we have uncovered new epitranscriptomic phenomena, such as <i>in situ</i> generation of non-native RNA modification, that offer fresh capabilities for cell imaging or targeted manipulation of plant callus development. Together, these discoveries sig","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":""},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aldehyde-Stabilization Strategies for Building Biobased Consumer Products around Intact lignocellulosic Structures.","authors":"Shasha Zheng, Songlan Sun, Lorenz P Manker, Jeremy S Luterbacher","doi":"10.1021/acs.accounts.4c00819","DOIUrl":"10.1021/acs.accounts.4c00819","url":null,"abstract":"<p><p>Dwindling fossil resources and their associated environmental concerns have increased interest in biobased products. In particular, many approaches to convert lignocellulosic biomass into small-molecule building blocks are being explored via thermal, chemical, and biological processes. Depending on their structure, these molecules can be used as direct (i.e., drop-in) or indirect (different molecule from what is used today) substitutes for petrochemicals. In all such cases, biomass must be deconstructed, which involves the depolymerization of lignin and polysaccharides as well as their further transformation to produce these substitutes. Deconstruction often requires harsh conditions that cause degradation, and further upgrading implies multiple conversion steps, especially for drop-in molecules, all of which lead to low atom economy. Our group has developed an aldehyde-stabilization strategy that facilitates the depolymerization of lignocellulose to monomers in high yields by stabilizing intermediates under biomass deconstruction conditions. This strategy has now been adapted to prepare indirect substitutes for petrochemicals with very high atom economy including biobased solvents, plastic precursors, adhesives, and surfactants, which have widespread applications in modern society.In this Account, we first introduce the function of aldehydes using formaldehyde (FA) as an example. Specifically, we discuss their role in assisting lignin isolation and their ability to stabilize lignin by looking at the lignin monomer yields that can be obtained after hydrogenolysis of the associated aldehyde-functionalized lignin. Highly selective production of lignin monomers was achieved using acetaldehyde (AA) or propionaldehyde (PPA) as a stabilization reagent via either reductive or oxidative depolymerization. In a typical FA-assisted fractionation, hemicellulose was directly converted into diformylxylose (DFX), while cellulose with properties similar to those obtained by organosolv was isolated but could be converted to diformyl-glucose isomers (DFGs) by further hydrolysis. These stable molecules provide us a new method to preserve sugar molecules that often degrade during acidic fractionation, which will be discussed in Section 3. Besides, DFX can also be used as a green solvent (Section 4), while FA-lignin exhibits excellent adhesion properties for plywood preparation (Section 5). Biobased glyoxylic acid (GA) was used to convert hemicellulose into a high yield of dimethylglyoxylic-acid-xylose (DMGX), a terephthalic acid (TA) substitute for bioplastics production (Section 6), while GA-lignin demonstrates great amphiphilic properties and finds applications as surfactants in cosmetic products (Section 7). When fatty aldehydes were used as stabilization reagents, both lignin and hemicellulose were converted to surfactants by downstream defunctionalization (Section 7). We will also discuss the current limitations of this aldehyde-stabilization strategy for","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"877-892"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening Liquid Crystal Elastomer Muscles.","authors":"Xiao Liu, Xiang Zhou, Zunfeng Liu","doi":"10.1021/acs.accounts.4c00842","DOIUrl":"10.1021/acs.accounts.4c00842","url":null,"abstract":"<p><p>ConspectusLiquid crystal elastomer fibers (LCEFs) are reversible artificial muscles capable of stimuli-responsive functions, making them promising competitors for ideal soft actuators. These remarkable actuation properties depend strongly on their mechanical properties, such as elastic modulus and breaking stress. It is necessary to strengthen the LCEF muscles to meet the demands of advanced applications. However, despite the significant progress in LCEFs, there is currently no such Account systematically summarizing and analyzing the strategies adopted for enhancing their mechanical and actuation properties. The intuitive variations among the different enhancement strategies further call for investigations into how to choose the most suitable ones based on specific situations. In this Account, for the first time, we systematically summarize existing approaches to strengthening LCEF-based artificial muscles, contributing to the development of more robust and smarter fibrous artificial muscles.In the first section, we focus on the latest and most valuable progress on strengthening LCEF-based artificial muscles, highlighting the need for a comprehensive summary of the various approaches utilized. The mechanical properties of LCEFs can be tailored through molecular design, physical interactions, and fiber integration. The adjustment of hard/soft segment features, the introduction of additional microstructures, and the fiber integration provide opportunities to strengthen LCEF-based artificial muscles, which are discussed in the second section. Subsequently, we delve into the impact of various preparation methods on the performance of LCEFs, and LCEFs fabricated by different spinning and alignment techniques exhibited rather different mechanical and actuation properties. This has been adopted to engineer novel, stronger, and tailored fibrous artificial muscles, as described in the third section. Moreover, we show that the incorporation of rigid composite materials via coating and doping has emerged as a powerful strategy to strengthen LCEFs, such as core-shell structures. Such enhancements also introduce multifunctionality for LCE-based artificial muscles that can enrich the fiber structure and actuation mechanism, which are elucidated in the fourth section. Finally, we conclude this Account with a critical analysis of the challenges and prospects of LCE-based artificial muscles, hoping to pave the way for the construction of more powerful fibrous artificial muscles.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"907-918"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering Reaction Mechanisms of Molecular Proton Reduction Catalysts with Cyclic Voltammetry: Kinetic vs Thermodynamic Control.","authors":"Jillian L Dempsey","doi":"10.1021/acs.accounts.5c00002","DOIUrl":"10.1021/acs.accounts.5c00002","url":null,"abstract":"&lt;p&gt;&lt;p&gt;ConspectusThe kinetics and thermodynamics of elementary reaction steps involved in the catalytic reduction of protons to hydrogen define the reaction landscape for catalysis. The mechanisms can differ in the order of the elementary proton transfer, electron transfer, and bond-forming steps and can be further differentiated by the sites at which protons and electrons localize. Access to fully elucidated mechanistic, kinetic, and thermochemical details of molecular catalysts is crucial to facilitate the development of new catalysts that operate with optimal efficiency, selectivity, and durability. The mechanism by which a catalyst operates, as well as the kinetics and thermodynamics associated with the individual steps, can often be accessed through electroanalytical studies.This Account details the application of cyclic voltammetry to interrogate reaction mechanisms and quantify the kinetics and thermodynamics of elementary reaction steps for a series of molecular catalysts that mediate electrochemical proton reduction. I distinguish the limiting scenarios wherein a catalyst operates under kinetic control vs thermodynamic control, with a focus on detecting how cyclic voltammetry features shift with proton source strength and concentration, as well as scan rate. For systems that operate under kinetic control, catalytic currents are observed at, or slightly positive toward, the formal potential for the redox process that triggers catalysis. Under thermodynamic control, catalytic responses shift as a function of the proton source p&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;a&lt;/sub&gt; and effective pH of the solution. After drawing this distinction, we introduce the appropriate voltammetry experiments and accompanying analytical expressions for extracting key metrics from the data.To illustrate analytical strategies to quantify elementary reaction steps of catalysts operating under kinetic control, I describe our studies of proton reduction catalysts Co(dmgBF&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;(CH&lt;sub&gt;3&lt;/sub&gt;CN)&lt;sub&gt;2&lt;/sub&gt; (dmgBF&lt;sub&gt;2&lt;/sub&gt; = difluoroboryl-dimethylglyoxime) and [Ni(P&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt;N&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (P&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt;N&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt; = 1,5-phenyl-3,7-phenyl-1,5-diaza-3,7-diphosphacyclooctane). Here, peak shift analysis, foot-of-the-wave analysis, and plateau current analysis are applied to data sets wherein voltammetric response are recorded as a function of catalyst concentration, proton source concentration, proton source strength, and scan rate to quantify rate constants for elementary proton transfer and bond-forming steps in a catalytic cycle. Further, the case study of [Ni(P&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt;N&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;Ph&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; illustrates how complementary spectroscopic methods can bolster the mechanistic assignment. Collectively, these two studies showcase how detailed mechanistic studies inform on rate-limiting elementary steps in catalysis and other key processes underpinni","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"947-957"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity-Generating Skeletal Editing Transformations.","authors":"Fu-Peng Wu, Jasper L Tyler, Frank Glorius","doi":"10.1021/acs.accounts.4c00820","DOIUrl":"10.1021/acs.accounts.4c00820","url":null,"abstract":"&lt;p&gt;&lt;p&gt;ConspectusSkeletal editing, as a synthetic tool, offers the unique potential to selectively and efficiently modify the core skeleton of a target molecule at a late-stage. The main benefit of such transformations is the rapid exploration of the chemical space around lead compounds without necessitating a &lt;i&gt;de novo&lt;/i&gt; synthesis for each new molecule. However, many skeletal editing transformations are inherently restricted to generating a single product from a single starting compound, limiting the potential for diversification, a concept central to expediting structure-activity relationship (SAR) investigations. In this Account, we describe our efforts to develop novel skeletal editing transformations in which a modification to the central motif of a molecule is performed simultaneously with the incorporation of additional functionality that can be easily varied through a judicious choice of the reagents. Specifically, we successfully developed an α-iodonium diazo-based carbynyl radical equivalent reagent that, under photoredox conditions, could facilitate the ring-expansion of indene scaffolds while enabling the insertion of over ten different functionalized carbon atoms into the corresponding naphthalene products. This concept was later extended to the design of an atomic carbon equivalent reagent that could promote mild and selective Ciamician-Dennstedt-type indole ring-expansion reactions, while simultaneously installing an oxime ester handle that could undergo further functionalization. Furthermore, we highlight recent work from our group on multiple-atom insertion reactions, namely, the development of a photocatalyzed De Mayo reaction for the ring-expansion of cyclic ketones and a photocatalyzed dearomative ring-expansion of thiophenes via small-ring insertion. In both of these cases, multiple products can be potentially accessed from a single starting material upon variation of the insertion reagent. The diversity-generating skeletal editing strategy could also be applied to single-atom transmutation, as demonstrated by the development of a nitrogen-to-functionalized carbon atom transmutation reaction to convert pyridine to benzene rings. Here, the desired transformation was achieved via a sequence of pyridine ring-opening, Horner-Wadsworth-Emmons (HWE) olefination, and ring-closure, with a judicious choice of the HWE reagent allowing the installation of a wide variety of versatile functional groups. Finally, an energy transfer-mediated quinoline ring-contraction is discussed, specifically with reference to the ways in which it does and does not fit the criteria of a skeletal editing reaction. Although formal atom deletion transformations are typically restricted to single products from each discrete substrate, this [2 + 2] cycloaddition/rearrangement cascade also involves the incorporation of an alkene into the molecule and introduces a point of variation that can be exploited for diversity generation. We hope to not only highlight ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"893-906"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterophase Junction Effect on Photogenerated Charge Separation in Photocatalysis and Photoelectrocatalysis.","authors":"Jing Zhang, Xiuli Wang, Xiang Wang, Can Li","doi":"10.1021/acs.accounts.4c00582","DOIUrl":"10.1021/acs.accounts.4c00582","url":null,"abstract":"&lt;p&gt;&lt;p&gt;ConspectusThe conversion of solar energy into chemical energy is promising to address energy and environmental crises. For solar conversion processes, such as photocatalysis and photoelectrocatalysis, a deep understanding of the separation of photogenerated charges is pivotal for advancing material design and efficiency enhancement in solar energy conversion. Formation of a heterophase junction is an efficient strategy to improve photogenerated charge separation of photo(electro)catalysts for solar energy conversion processes. A heterophase junction is formed at the interface between the semiconductors possessing the same chemical composition with similar crystalline phase structures but slightly different energy bands. Despite the small offset of Fermi levels between the different phases, a built-in electric field is established at the interface of the heterophase junction, which can be the driving force for the photogenerated charge separation at the nanometer scale. Notably, slight variations in the energy band of the two crystalline phases result in small energy barriers for the photogenerated carrier transfer. Moreover, the structural similarity of the two different crystalline phases of a semiconductor could minimize the lattice mismatch at the heterophase junction, distinguishing it from a p/n junction or heterojunction formed between two very different semiconductors.This Account provides an overview of the understanding, design, and application of heterophase junctions in photocatalysis and photoelectrocatalysis. It begins with a conceptualization of the heterophase junction and reviews recent advances in the synthesis of semiconductors with a heterophase junction. The phase transformation method with the advantage of forming a heterophase junction with an atomically matched interface and the secondary seed growth method for unique structures with excellent electronic and optoelectronic properties are described. Furthermore, the mechanism of the heterophase junction for improving the photogenerated charge separation is discussed, followed by a comprehensive discussion of the structure-activity relationship for the heterophase junction. The home-built spatially resolved and time-resolved spectroscopies offer direct imaging of the built-in electric field across the heterophase junction and then the direct detection of the photogenerated charge transfer between the two crystalline phases driven by the built-in electric field. Such an efficient interfacial charge transfer results in the improvement of the photogenerated charge separation, a higher yield of long-lived charges, and thus the inhibition of the charge recombination. Benefiting from these insights, structural design strategies for the heterophase junction, such as precise tuning of band alignment, exposed heterophase amounts, phase alignment, and interface structure, have been developed. Finally, the challenges, opportunities, and perspectives of heterophase junctions in the","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":" ","pages":"787-798"},"PeriodicalIF":16.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Striving to Disclose the Electrochemical Processes of Organic Batteries","authors":"Haoyu Guo,&nbsp;Qun Liu and Chengliang Wang*,&nbsp;","doi":"10.1021/acs.accounts.5c0002810.1021/acs.accounts.5c00028","DOIUrl":"https://doi.org/10.1021/acs.accounts.5c00028https://doi.org/10.1021/acs.accounts.5c00028","url":null,"abstract":"&lt;p &gt;Organic/polymeric materials are promising as electrode materials for batteries because of their advantages of flexibility, high specific capacity due to the possible multielectron transfer, low cost from green natural resources, and weak intermolecular interactions that enable the storage of low-cost large-sized or multivalent metal ions. However, the development of organic electrode materials (OEMs) and organic batteries and the understanding of the electrochemical process face great challenges in the characterization of polymers and the charge storage mechanisms: (1) the charged and/or discharged states of OEMs are often air unstable, which makes the ex situ characterizations susceptible to the interference of air. (2) OEMs, particularly polymeric materials, are designed to be insoluble to deliver high cyclability, which makes it difficult for them to be separated from the electrode. (3) Possible multielectron transfer makes it difficult to determine whether the proposed charge storage mechanism or the experiment results are wrong when the actual capacity mismatches with the theoretical capacity based on the proposed mechanisms. (4) It is difficult to achieve single crystals of polymers, and hence, it seems impossible to know the actual locations of the stored ions in the polymers. (5) The typical methods for characterization of insoluble polymers are only qualitative, and it is challenging to quantify the amount of stored ions. (6) Even for most in situ characterizations, they can only give the tendency of qualitative structural evolution.&lt;/p&gt;&lt;p &gt;In this Account, we give an overview of the significance of organic batteries and the challenges related to the characterization and charge storage mechanisms of organic electrode materials. Then, we summarize our efforts in recent years to reveal the charge storage mechanisms and insights into the electrochemical process. Focusing on the complexity of polymer materials, we proposed a strategy to control the reaction kinetics in order to obtain high-quality single crystals or microcrystals of polymers. The chemical structure and reaction mechanism of polymers could be successfully revealed by single crystal structure analysis. To avoid the inconvenient characterizations brought by the insolubility of polymers, soluble monomers or oligomers were studied under the same conditions to simulate and analyze the electrochemical process of polymers. We also proposed the synthesis of isomers for a deep understanding of the structure–property relationships of OEMs. On the other hand, traditional qualitative characterization instruments or techniques were reconsidered to give more information or even quantitative results via insightful analysis of the data or smart design of experiments. In addition, by introducing internal standard substances, it was also possible to realize quantitative characterizations. Strategies to convert the black box of different charged/discharged states into detectable materials ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"58 7","pages":"1120–1133 1120–1133"},"PeriodicalIF":16.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Striving to Disclose the Electrochemical Processes of Organic Batteries","authors":"Haoyu Guo, Qun Liu, Chengliang Wang","doi":"10.1021/acs.accounts.5c00028","DOIUrl":"https://doi.org/10.1021/acs.accounts.5c00028","url":null,"abstract":"Organic/polymeric materials are promising as electrode materials for batteries because of their advantages of flexibility, high specific capacity due to the possible multielectron transfer, low cost from green natural resources, and weak intermolecular interactions that enable the storage of low-cost large-sized or multivalent metal ions. However, the development of organic electrode materials (OEMs) and organic batteries and the understanding of the electrochemical process face great challenges in the characterization of polymers and the charge storage mechanisms: (1) the charged and/or discharged states of OEMs are often air unstable, which makes the ex situ characterizations susceptible to the interference of air. (2) OEMs, particularly polymeric materials, are designed to be insoluble to deliver high cyclability, which makes it difficult for them to be separated from the electrode. (3) Possible multielectron transfer makes it difficult to determine whether the proposed charge storage mechanism or the experiment results are wrong when the actual capacity mismatches with the theoretical capacity based on the proposed mechanisms. (4) It is difficult to achieve single crystals of polymers, and hence, it seems impossible to know the actual locations of the stored ions in the polymers. (5) The typical methods for characterization of insoluble polymers are only qualitative, and it is challenging to quantify the amount of stored ions. (6) Even for most in situ characterizations, they can only give the tendency of qualitative structural evolution.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"33 1","pages":""},"PeriodicalIF":18.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}