Accounts of Chemical Research最新文献

{"title":"Investigating Structural Heterogeneities of Amyloid Aggregates with Spatially Resolved Infrared Spectroscopy","authors":"Divya Baghel, Ayanjeet Ghosh","doi":"10.1021/acs.accounts.6c00390","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00390","url":null,"abstract":"<p>The aggregation of proteins into fibrillar amyloidsis centralto the pathology of neurodegenerative disorders. However, the relationshipbetween the structure of amyloid aggregates and disease progressionremains incompletely understood, in part because amyloid systems areintrinsically heterogeneous: structurally distinct species coexistat every stage of aggregation, and conventional ensemble-averagedmethods cannot always resolve them. This Account describes how infraredspectroscopy can be coupled to different imaging modalities to resolvethis heterogeneity at multiple length scales: from single-aggregatelevel to amyloid species in diseased brain tissues.</p><p>Our findingsdemonstrate that (i) early stage tau fibrils exhibitpronounced structural polymorphism without morphological differences,converging to a single dominant conformation upon maturation thatunexpectedly includes antiparallel β-sheet structure; (ii) Aβ42oligomeric heterogeneity propagates through protofibrils into fibrils,where structurally distinct domains coexist along a single fibril,demonstrating that amyloid fibrils can deviate significantly fromthe canonical parallel cross-β architecture; (iii) Aβ(16–22)fibrils undergo a parallel-to-antiparallel β-sheet transitionduring maturation through disordered intermediates without morphologicalchange, providing direct evidence of spontaneous structural reorganizationin fibrillar species. Beyond single-protein systems, (iv) Aβ42forms structurally distinct mixed polymorphs when aggregated withsequentially or structurally heterotypic seeds and when coaggregatedwith α-synuclein, establishing heterotypic interactions as anunderappreciated source of aberrant aggregate structures; (v) coaggregationof Aβ with the islet amyloid polypeptide (IAPP) from the monomericstate produces a unique heterotypic polymorph in which both peptidesadopt non-native structures, whereas cross-seeding with preformedIAPP fibrils yields predominantly homotypic Aβ aggregates, demonstratingthat conformational flexibility at the monomeric stage is requiredfor heterotypic fibril formation. These molecular-level findings arecomplemented by tissue-scale evidence: (vi) discrete frequency IRimaging reveals that amyloid plaques in AD brain exhibit chemicaland structural heterogeneities not reflected in morphology, consistentwith in vitro observations; and (vii) optical photothermal infrared(O-PTIR) spectroscopic imaging of vascular amyloid deposits in cerebralamyloid angiopathy (CAA) reveals a disease-stage-dependent increasein antiparallel β-sheet content that correlates specificallywith colocalized lipids, recapitulated in vitro by coaggregating Aβ40with lipid extracts. Collectively, these findings support the viewthat structural heterogeneity is not merely an artifact of in vitroconditions but a property that can persist in human brain tissuesand illustrate how spatially resolved IR spectroscopy can complementcryogenic electron microscopy (cryo-EM) and solid-state NMR in th","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3294–3307"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218993","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":"Sulfur-Substitution as a Design Principle for Closed-Loop Plastics: Dithiolactones, Monothiodilactones, and Beyond","authors":"Yanchao Wang, Xue Wang, Youhua Tao","doi":"10.1021/acs.accounts.6c00551","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00551","url":null,"abstract":"<p>Plastics capable of true closed-looprecycling require moleculardesign strategies that reconcile polymerizability, recyclability,and high material performance within a single system. Yet many chemicallyrecyclable polymers remain limited by narrow monomer scope, inefficientdepolymerization, or the persistent trade-off between recyclabilityand useful material properties. While most established systems havearisen from oxygen-based cyclic monomers, sulfur substitution offersa conceptually distinct route by reshaping ring-closing tendencies,polymerization behavior, and end-of-life depolymerization pathways.</p><p>In this Account, we summarize how sulfur substitution evolved inour work from an initial polymerization insight into a broader designprinciple for closed-loop plastics. This story begins with <em>S</em>-carboxyanhydrides (SCAs), whose ultrafast and selectivering-opening polymerization first demonstrated the synthetic potentialof sulfur-containing cyclic monomers for well-defined polythioesters.During these studies, a thermodynamic comparison between thiolacticacid-derived SCAs and sulfur-substituted lactide analogues unexpectedlyrevealed that thiolactide exhibits near-equilibrium polymerizationthermodynamics. This finding identified dithiolactones as promisingclosed-loop monomer candidates and led to a systematic explorationof sulfur-substituted cyclic esters.</p><p>We then show how this designlogic was established with dithiolactonesand further developed through stereocontrolled polymerization. Dithiolactonesdemonstrated that O-to-S substitution can rebalance conflicting cyclizability,polymerizability, and recyclability. Building on this foundation,ligand-tailored salen-Al catalysis, covalent borane-thiourea organocatalysis,and quaternary ammonium/thiophenolate ion-pair catalysis consistentwith nonclassical C–H···X interactions expandeddithiolactones into a stereocontrolled platform. These complementarystrategies enabled high-molecular-weight, stereoregular, and chemicallyrecyclable polythioesters from both enantiopure and racemic dithiolactones.Monothiodilactones, in turn, refined this design logic by showinghow partial sulfur substitution can improve regio- and chemoselectivitywhile suppressing deleterious transthioesterification. Beyond thesemonomer platforms, interfacial chain-growth polymerization ultimatelytranslated sulfur substitution into high-molecular-weight, polypropylene-likecircular polythioglycolide (PTGA), thereby demonstrating the materialpotential of this design principle.</p><p>Overall, this Account presentssulfur substitution not only asa structural modification but also as a design principle connectingmonomer thermodynamics, stereochemical control, materials performance,and closed-loop recovery. More broadly, this Account highlights sulfursubstitution as a versatile molecular design strategy for integratingpolymerization control, material performance, and closed-loop recyclabilityin next-generation circular plastics.</","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3413–3425"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218988","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":"From Anti-Sintering to Anti-Dispersion: Preserving Reactive Metallic Pt Ensembles in Light-Alkane Oxidation","authors":"Xuan Tang,Lide Yang,Sheng Dai,Yun Guo","doi":"10.1021/acs.accounts.6c00721","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00721","url":null,"abstract":"A long-standing principle in supported noble-metal catalysis is to maximize metal dispersion and prevent nanoparticle sintering. This dispersion-centered, anti-sintering paradigm is rational because highly dispersed species increase apparent metal utilization and often expose low-coordinated sites with distinct electronic structures. For low-temperature oxidation of C2+ light alkanes, however, dispersion alone does not define the working catalyst. Propane is considered here as a representative model because its complete oxidation couples initial alkane adsorption and C–H activation with subsequent dehydrogenation, C–C bond cleavage, and deep oxidation of Cx intermediates. These functions require a balance between alkane-accessible metallic Pt ensembles and oxygen or interfacial functions that sustain complete oxidation. Excessive dispersion can disrupt this balance by promoting Pt oxidation, strong oxygen binding, or stabilization of isolated species, whereas less-dispersed Pt can preserve the contiguous metallic sites needed for alkane activation under suitable reaction conditions.\u0000In this Account, we propose anti-dispersion as a design concept for constructing and preserving the appropriate working Pt ensemble. Pt dispersion is treated not as a monotonic activity descriptor but as a reaction-dependent variable coupled to metallic character, ensemble availability, oxygen coverage, accessible-site density, and support anchoring. Anti-dispersion therefore encompasses both controlled restructuring of over-dispersed Pt into reactive metallic ensembles and prevention of their subsequent fragmentation under working conditions. Our studies reveal these two complementary dimensions. Size-controlled Pt/CeO2 model catalysts show that increasing Pt size can enhance metallic character and intrinsic activity for propane oxidation, while the overall rate reflects a trade-off between ensemble reactivity and exposed-site density. Controlled sintering of Pt on MgAl2O4 further demonstrates that lower dispersion can be beneficial when it generates metallic surfaces that remain alkane-accessible within the relevant oxygen-coverage window. Conversely, active metallic Pt ensembles on CeO2 can fragment during propane oxidation and become stabilized as isolated Pt spectators. Selective blocking of the corresponding atom-trapping sites suppresses this reaction-induced redispersion and preserves metallic Pt ensembles. Extending this concept across oxide supports shows that anti-dispersion must be adapted to the dominant anchoring environment. Depending on the support, the relevant strategy may involve blocking support-templated Pt oxide formation, moderating acid-site-mediated anchoring, or competitively occupying hydroxyl sites that otherwise over-disperse Pt. The unifying objective is to regulate the anchoring landscape selectively while retaining useful interfacial functions for oxygen management, Cx-intermediate conversion, water tolerance, and durability.\u0000Together, ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"42 1","pages":""},"PeriodicalIF":18.3,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221797","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":"Confined Growth of MOFs into Angstrom-Scale Defect-Free Membranes for Precise Molecular Separation","authors":"Guozhen Liu, Jingui Duan, Gongping Liu, Wanqin Jin","doi":"10.1021/acs.accounts.6c00597","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00597","url":null,"abstract":"<p>Metal–organic frameworks(MOFs), featuring ordered nanochannelsand versatile pore chemistry, have emerged as promising materialsfor developing next-generation separation membranes. MOF-based membranesare typically synthesized either by the intergrowth of crystals toform polycrystalline membranes or by incorporating crystals into polymersto form mixed-matrix membranes (MMMs). During the membrane formationprocesses, multiscale defects─ranging from microscale intercrystallinecracks and nanoscale interfacial gaps to angstrom-scale lattice defects─areprone to arise. These undesirable defects compromise the membranestructural integrity and molecular transport properties, thus impairingthe separation efficiency and impeding the implementation of MOF-basedmembranes for precise molecular separation.</p><p>In this Account,we present our group’s efforts to constructdefect-free molecular sieving membranes based on the “confinedgrowth of MOFs”. We first establish MOF design and selectionprinciples by correlating molecular transport mechanisms with frameworkcharacteristics. We then demonstrate how confined growth enables theelimination of multiscale defects in both polycrystalline membranesand MMMs. For polycrystalline membranes, the elimination of angstrom-scalelattice defects has been a long-standing challenge. To address this,we proposed a high-probability theoretical coordination strategy thatcreates sufficient chemical potential to overcome the steric hindrancethat occurs when connecting ligands to metal clusters. By furtherregulating the confinement of coordination reactants (e.g., ligands,metal cluster precursor), coordination environment (e.g., solvent,modulator), and coordination space (e.g., pore size, topology), weinhibited the linker-missing and metal cluster-missing defects andrestored intrinsic lattice integrity in MOF membranes. This leadsto a family of high-connectivity MOF membranes exhibiting outstandingmolecular separation performance, not only for gases but also forwater/ions and organic mixtures. By employing atomic-level characterizations(e.g., real-space high-resolution transmission electron microscopy)and molecular simulations, we revealed the underlying thermodynamicsand kinetic mechanism of defect suppression and confined moleculartransport through the lattice aperture. For MMMs, despite the structuralintegrity achieved in the as-synthesized crystals, incorporating thesecrystals into polymers remains another grand challenge because thisprocess often introduces multiscale defects resulting from filleraggregation and interfacial incompatibility. Recognizing that thespace between MOF fillers and the polymer matrix represents a typicalconfined environment, we pursued molecular-confined strategies tosolve the dispersion and compatibility issues in MMMs. Recently, weproposed a solid-solvent processing strategy to fabricate an ultrathinand highly loaded defect-free MMM for molecular sieving. The polymerserves as a solid solvent, confining ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3560–3575"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218973","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":"Electrochemically Supported Asymmetric Synthesis on Chiral Encoded Pt and Pt–Ir Surfaces","authors":"Anousha Sohail,&nbsp;Wanmai Srisuwanno,&nbsp;Sopon Butcha,&nbsp;Alexander Kuhn,&nbsp;Chularat Wattanakit","doi":"10.1021/acs.accounts.6c00499","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00499","url":null,"abstract":"<p>In recent years, we studiedthe design of chiral-encoded metalsurfaces via electrodeposition as a platform for heterogeneous asymmetricsynthesis, where stereochemical information is intrinsically embeddedwithin metallic architectures together with mesoporous structures.By using lyotropic liquid crystal templating and chiral molecularimprinting, it is possible to elaborate chiral-encoded mesoporousmetal electrodes by electrodeposition, particularly Pt or Pt–Irsystems, with chiral recognition sites that enable ligand-free enantioselectivetransformations. These designer materials exhibit high surface area,efficient mass transport, and structural robustness, overcoming keylimitations of traditional enantioselective catalysis such as poorrecyclability and limited stability.</p><p>Our studies demonstratethat the chiral interfaces enable highlyenantioselective electrosynthesis of chiral compounds, achieving upto 95% ee with excellent durability. In addition, we implemented severalconcepts to enhance the enantiomeric excess, for example, pulsed electrosynthesis,and self-assembled monolayer protection of chiral-imprinted metalsurfaces for highly enantioselective electrosynthesis. Furthermore,we also extended the concept to heterogeneous catalysis for asymmetricsynthesis of chiral molecules, in particular, pharmaceutically relevantcompounds, eventually achieving up to 95% ee with excellent durabilityand compatibility with flow-based systems.</p><p>We also integratedthese materials into autonomous systems, developingchiral metal microswimmers that combine self-propulsion with enantioselectivecatalysis, thus enabling self-mixing. Despite ongoing challenges instabilizing the imprinted chiral information, the broadening of thisconcept to other metals, such as multimetallic and non-noble systems,offers promising solutions. Taken together, these advancements establishthis approach to create chiral-encoded metal surfaces as a versatileconcept for the next generation of chiral-imprinted metals for sustainableasymmetric synthesis.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3347–3358"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218981","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":"Catalytic MOFs under Operation: From Static Descriptors to Dynamic Mechanistic Control","authors":"Zheao Huang,&nbsp;Shaghayegh Naghdi,&nbsp;Pablo Ayala,&nbsp;Dominik Eder","doi":"10.1021/acs.accounts.6c00529","DOIUrl":"10.1021/acs.accounts.6c00529","url":null,"abstract":"<p>Metal–organic frameworks(MOFs) have traditionally beenviewed as ideal heterogeneous catalysts because their crystallographicprecision enables atomic-level structure–property correlations.Yet our work repeatedly showed that catalytic turnover rarely occurson these idealized structures. Instead, active sites continuouslyevolve through substrate adsorption, transient coordination changes,charge redistribution, and surface reconstruction. The central challengeis therefore not simply designing stable frameworks but designingframeworks whose structural evolution remains mechanistically predictable.Therefore,how should structurally well-defined MOFs be interpreted as catalystswhen their actual function depends not only on the as-synthesizedlattice but also on this inevitable structural evolution during operation?We argue that this question extends beyond MOFs. Many modern heterogeneouscatalysts─including oxides, single-atom catalysts, and coordinationpolymers─operate through dynamic active sites whose structurediffers from the as-synthesized material. MOFs provide an unusuallywell-defined platform for understanding these transformations becauseboth the starting structure and the subsequent evolution can be experimentallyresolved. In this Account, we outline a necessary shift in MOF catalysisfrom treating static descriptors as universally predictive to controllingdynamic reaction mechanisms based on their elementary steps. To bridgethis gap between idealized models and operational realities, we developedthe framework-retaining selective ligand removal (SeLiRe) strategy.By exploiting the differential lability of mixed ligands, SeLiRe generatesdeterministic open metal sites and hierarchical pores across bothhard–hard and soft–soft coordination networks withoutfully sacrificing the parent topology. We further investigated chargegeneration and extraction dynamics, demonstrating how modificationsintended to improve optical absorption can inadvertently alter chargelocalization and introduce kinetic traps, while the dimensionalityof inorganic secondary building units fundamentally dictates chargecarrier lifetimes. Transitioning to harsher electrocatalytic regimes,we employ operando spectroscopy to capture the potential-driven evolutionof these static open metal nodes. Specifically, we tracked the <em>in situ</em> transformation of low-valence sites into highlyreactive, hydroxylated transient intermediate states alongside thecontrolled reconstruction of bulk frameworks into highly conductivesurfaces. We propose that the principal advantage of MOFs is not thatthey remain structurally invariant during catalysis, but that theyprovide an experimentally accessible platform in which structuralevolution can be designed, monitored, and mechanistically interpreted.This perspective shifts catalyst design from optimizing static descriptorstoward engineering controlled dynamic active sites.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3387–3399"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049374","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":"Transient Directing Groups for Enhancing Affinity between Native Substrates and Transition Metal C–H Activation Catalysts","authors":"Jordan R. Yirak,&nbsp;Zhen Wang,&nbsp;Martin Tomanik,&nbsp;Yan-Qiao Chen,&nbsp;Kevin Wu,&nbsp;Jin-Quan Yu","doi":"10.1021/acs.accounts.6c00521","DOIUrl":"10.1021/acs.accounts.6c00521","url":null,"abstract":"<p>In the past two decades, transitionmetal-catalyzed C–Hactivation has emerged as an attractive and valuable strategy forenabling novel disconnections in the synthesis of natural productsand pharmaceuticals. Substrate-directed C–H activation, whichemploys pre-coordination of a substrate’s functional groupwith the catalyst to recruit it for C–H metalation with highsite-selectivity, is a particularly powerful approach. Early directedC–H activations relied on bespoke directing groups with separateinstallation and removal steps, reducing synthetic efficiency andpracticality (limited functional group tolerance, substrate scope).The development of C–H activation methods which use functionalgroups native to common building blocks and synthetic intermediateswould be highly valuable.</p><p>In this account, we highlight thediscovery and development ofa transient directing group (TDG) platform for Pd-catalyzed C–Hactivation reactions of native aldehydes, ketones, and amines. Thisapproach leverages the reversible imine formation event between thesubstrate and a complementary TDG motif to transiently generate theoptimal L,X-type assembly capable of recruiting Pd catalysts for adiverse range of C–H activation reactions, including C–C,C–halogen, C–O, and C–N bond formations. We alsodescribe the application of pyridone ligands in concert with the TDGapproach to amplify the reactivity of the Pd catalysts and to activatepreviously inaccessible C–H bonds. Finally, we cover notableapplications of Pd-catalyzed TDG C–H activation in complexmolecule synthesis.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3481–3499"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151564","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":"Functionalized Fullerenes in Perovskite Photovoltaic Devices","authors":"Zhou Xing,&nbsp;Luis Echegoyen,&nbsp;Su-Yuan Xie,&nbsp;Chengbo Tian","doi":"10.1021/acs.accounts.6c00454","DOIUrl":"10.1021/acs.accounts.6c00454","url":null,"abstract":"&lt;p&gt;Perovskite photovoltaic (PV)technology offers outstanding advantages,making it a research hotspot for next-generation solar cells and securinga key strategic position in the field of clean energy. Within thistechnological framework, fullerenes have become indispensable keyfunctional components in perovskite PV devices, attracting widespreadattention from both academia and industry due to their high electronaffinity, three-dimensional electron transport properties, and excellentdefect-passivation capability. However, the application of pristinefullerene C&lt;sub&gt;60&lt;/sub&gt; in perovskite solar cells (PSCs) is stillhindered by several limitations, including poor solubility in commonsolvents, suboptimal energy level alignment with different perovskites,and insufficient passivation of defects at the perovskite interfaces.These issues restrict further improvements in both device efficiencyand long-term operational stability. To address these bottlenecks,various solution strategies have been reported from different perspectives.Nevertheless, a systematic view spanning from molecular design todevice integration is still lacking. Driven by the rapid developmentsof PSCs, the core contribution of our team lies in the design andsynthesis of a series of functionalized fullerene derivatives throughprecise molecular engineering strategies, and their systematic integrationas multifunctional modules into different critical interfaces andthe bulk phase of perovskite PV devices. In this Account, we systematicallysummarize the principles of molecular design, chemically tailoredsynthetic strategies to meet diverse functional requirements, multiscaleintegration methodologies within device architectures, and the underlyingmechanisms that contribute to the comprehensive enhancement of deviceperformance. Particular emphasis is placed on elucidating how functionalizationinfluences critical processes such as film morphology, electron transportcharacteristics, charge recombination suppression, and ion migrationinhibition, thereby revealing the intrinsic rules by which these materialsgovern device efficiency and stability. Furthermore, we discuss thepotential of emerging endohedrally functionalized metallofullerenes,along with current challenges in the field, including multiple integrationswith tandem/flexible/commercial-size devices, the synthetic complexityand cost control of fullerenes, and their application possibilityin emerging lead-free PSCs, which seeks to elucidate the multifacetedroles of exo- and endofunctionalized fullerenes in PSCs. Finally,we present an outlook on future research directions for functionalizedfullerenes, aiming to drive progress toward high-efficiency, stable,and industrially scalable PSCs. We believe this Account will attractbroad interest from researchers in the fields of perovskite photovoltaics,organic electronics, and carbon nanomaterials science, thereby promotingfundamental research and industrial applications of functional carbonnanomateri","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3323–3335"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148973728","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":"Methylaluminoxane’s Molecular Cousins: Well-Defined Aluminum-Alkyl Borate Salts as Cocatalysts for Olefin Polymerization","authors":"Francesco Zaccaria,&nbsp;Roberta Cipullo,&nbsp;Cristiano Zuccaccia,&nbsp;Christian Ehm,&nbsp;Vincenzo Busico,&nbsp;Alceo Macchioni","doi":"10.1021/acs.accounts.6c00575","DOIUrl":"https://doi.org/10.1021/acs.accounts.6c00575","url":null,"abstract":"<p>The success story of molecularolefin polymerization has two protagonists,group 4 metal precatalysts and group 13 cocatalysts, which play equallyimportant roles but have evolved at very different paces. Precatalystdesign has shown tremendous progress over the past decades. Conversely,cocatalyst development has almost reached a standstill after methylaluminoxane(MAO) and organic borate salts/tri<em>-iso</em>-butylaluminum(TIBAL) binary systems were introduced in the 1980s–1990s.The complexity of innovating cocatalysts arises from the multifacetedroles that they fulfill and the numerous subtleties presiding overtheir reactivity. Major limitations persist, mostly related to thecomplex structure of MAO, hampering rational tuning, and to boratesalts being “incomplete” activators, since they functiononly as alkyl abstractors.</p><p>Recently, we identified an innovativecocatalyst providing comparableperformance to these established activators while combining theirdistinctive advantages. This system is based on a borate salt of anunusual dinuclear aluminum-alkyl cation, {[<em>i</em>Bu₂(DMA)Al]₂(μ-H)}[B(C₆F₅)₄] (<strong>AlHAl_DMA</strong>; DMA = <em>N</em>,<em>N</em>-dimethylaniline), which behaves as a single-component“complete” cocatalyst like MAO, while featuring a well-definedmolecular structure like traditional organic borate salts. This speciescan activate both dialkyl and dichloride precatalysts even in stoichiometricamounts, that is, orders of magnitude lower than those required withMAO. Moreover, it efficiently scavenges impurities, enabling olefinpolymerization at catalyst concentrations as low as 10^–7 M. Its well-defined structure provides opportunities for reactivitymodulation.</p><p>This Account summarizes the discovery of <strong>AlHAl_DMA</strong>, contextualizing it in the chemistry of olefin polymerization catalysisand organoaluminum compounds. The main features of this novel cocatalystare discussed by comparing its polymerization performance to thoseof established cocatalysts. Representative examples also illustrateavenues for polymer microstructure modulation upon substitution ofMAO and borate salt/TIBAL with <strong>AlHAl_DMA</strong>. Structuraltuning approaches are presented, showing that a novel class of innovativealuminum alkylborate (AAB) salts can be accessed. Some of these novelAAB salts also served as model species to trace the fundamental reactivityof <strong>AlHAl_DMA</strong>. Finally, this Account highlights futurechallenges in the cocatalyst development for olefin polymerization.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3500–3516"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218994","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":"Metalloporphyrins and Metallocorroles with Designed Second-Sphere Structures for Catalytic Small Molecule Activation Reactions","authors":"Tao Liu,&nbsp;Jinxiu Han,&nbsp;Haonan Qin,&nbsp;Haitao Lei,&nbsp;Xialiang Li,&nbsp;Rui Cao","doi":"10.1021/acs.accounts.6c00507","DOIUrl":"10.1021/acs.accounts.6c00507","url":null,"abstract":"&lt;p&gt;Small-molecule activation reactions, includingthe oxygen reductionreaction (ORR), hydrogen evolution reaction (HER), and carbon dioxidereduction reaction (CO&lt;sub&gt;2&lt;/sub&gt;RR), are involved in natural andartificial energy conversion processes. In enzymes, the second-sphereenvironment of catalytic sites can promote substrate activation, stabilizeintermediates, and facilitate proton transfer. Synthetic chemistshave endeavored to develop molecular catalysts with functionalizedsecond sphere environments. However, installing functional groupsat metal second-sphere sites and understanding their actual rolesin promoting reactions are proven to be challenging.&lt;/p&gt;&lt;p&gt;This Accountdescribes our recent works in developing metalloporphyrinsand related metallocorroles with designed second-sphere structuresfor ORR, HER, and CO&lt;sub&gt;2&lt;/sub&gt;RR. Metalloporphyrins are ideal platformsfor installing second-sphere groups and investigating their rolesin catalysis. We designed and synthesized a series of metalloporphyrinsby installing different substituents to construct molecular pockets,grab second metal ions, and introduce positively charged or hydrogen-bondinginteractions. Importantly, we focus on discussing the roles of thesesecond-sphere structures in improving the catalysis.&lt;/p&gt;&lt;p&gt;We usedmolecular pockets to stabilize active ORR intermediates.By using the αααα atropisomer of Co tetra(2-pivalamidophenyl)porphyrin,we synthesized Co&lt;sup&gt;III&lt;/sup&gt;-superoxo, Co&lt;sup&gt;III&lt;/sup&gt;-hydrosuperoxo,and Co&lt;sup&gt;III&lt;/sup&gt;-hydroperoxo, and more importantly, studied theirspectroscopic and reaction natures. By modifying the pocket structure,we revealed thermodynamic and kinetic control effects of the molecularpocket on O&lt;sub&gt;2&lt;/sub&gt; binding and provided new understanding ofsteric effects on catalytic ORR.&lt;/p&gt;&lt;p&gt;We appended a second metalion above the porphyrin macrocycle topromote O&lt;sub&gt;2&lt;/sub&gt; binding at metalloporphyrin sites by stabilizingthe resulted O&lt;sub&gt;2&lt;/sub&gt; adducts. By appending a strong Lewis acidicbut redox-inactive Sc&lt;sup&gt;3+&lt;/sup&gt; ion on Co&lt;sup&gt;III&lt;/sup&gt; corrole,we realized O&lt;sub&gt;2&lt;/sub&gt; activation at high-valent Co&lt;sup&gt;III&lt;/sup&gt; site, while by appending a redox-active Co&lt;sup&gt;II&lt;/sup&gt; ion on Co&lt;sup&gt;III&lt;/sup&gt; corrole, we could activate O&lt;sub&gt;2&lt;/sub&gt; by using two electronsto generate bridging peroxo. Moreover, the appended metal ion canassist O–O bond cleavage by accepting the leaving hydroxylgroup.&lt;/p&gt;&lt;p&gt;We introduced second-sphere groups to promote substratebindingand proton transfer through electrostatic and/or hydrogen-bondinginteractions. Appended cationic substituents improve the binding ofO&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; via electrostatic interactions. Importantly,we demonstrated role-specialized cooperation between two appendedcationic groups in the CO&lt;sub&gt;2&lt;/sub&gt;RR. In addition to stabilizingCO&lt;sub&gt;2&lt;/sub&gt; adducts, the two cationic groups can function differentlybut cooperatively to facilitate C–O bond cleavage. Appendedcrown ether can construct water networks for ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":"59 20","pages":"3359–3374"},"PeriodicalIF":18.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049393","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}