ACS Physical Chemistry Au最新文献

{"title":"Descriptor-Based Insights into Hydrazine Selectivity in Electrochemical Ammonia Oxidation on Single-Atom Centers of MXenes","authors":"Totan Mondal,&nbsp;Kai S. Exner","doi":"10.1021/acsphyschemau.6c00051","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00051","url":null,"abstract":"<p>Selective electrochemicalsynthesis of hydrazine (N₂H₄) from ammonia oxidationoffers a promising routetowardvalue-added nitrogen chemicals but remains challenging due to competingoxidation pathways. Here, density functional theory calculations areemployed to investigate hydrazine formation at electrochemically formedsingle-atom centers on 14 carbide- and nitride-based MXenes (MXene-SACs).Hydrazine selectivity is assessed using three descriptors, namelythe thermodynamic free-energy span <em>G</em>_max(<em>U</em>), the kinetic descriptor <em>G</em>^‡(<em>U</em>) associated with the N–Ncoupling activation barrier, and the hydrazine desorption energy (Δ<em>G</em>_des) governing product release from the catalyticsurface. Evaluation of <em>G</em>_max(<em>U</em>) identifies Nb₂C-, V₂C-, Cr₂C-,and V₂N-SAC motifs as promising materials for efficienthydrazine formation. However, transition state calculations for N–Ncoupling barriers modify the thermodynamic activity trends, as reflectedby <em>G</em>^‡(<em>U</em>), andindicate that selectivity remains generally biased toward N₂ formation. A combined descriptor assessment shows that carbide-basedMXene-SAC motifs, particularly V₂C and Cr₂C,remain the most promising hydrazine-competitive candidates due totheir balanced intermediate stabilization and favorable desorptionenergetics, while V₂N-SAC lies closest to the ideal hydrazine-selectiveregime in descriptor space. Overall, the descriptor-guided screeningstrategy provides a transferable basis for analyzing catalyst selectivitytoward hydrazine formation in ammonia electro-oxidation and relatedcatalytic systems.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1131–1143"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preferential Solvation of Mg2+ in Ethanol–Water Mixtures Probed by Intermolecular Coulombic Decay and Molecular Dynamics Simulations","authors":"Ouassim Hocine Hafiani,&nbsp;Alexandre M. Pereira,&nbsp;Luciano T. Costa,&nbsp;Michele Pugini,&nbsp;Shirin Gholami,&nbsp;Nicolas Velasquez,&nbsp;Florian Trinter,&nbsp;Iyas Ismail,&nbsp;Ricardo Marinho,&nbsp;Alexandra Mocellin,&nbsp;Arnaldo Naves de Brito,&nbsp;Carl Caleman,&nbsp;Lukáš Tomaník,&nbsp;Bernd Winter,&nbsp;Olle Björneholm,&nbsp;Gunnar Öhrwall","doi":"10.1021/acsphyschemau.6c00039","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00039","url":null,"abstract":"<p>The microsolvationof Mg²⁺ ions in ethanol–watermixtures was investigated using intermolecular Coulombic decay (ICD)after Mg 1s ionization, a nonlocal relaxation process involving theejection of valence electrons from molecules in the first solvationshell. As the solvent composition shifts from pure water to pure ethanol,the ICD spectral shape evolves, and its total intensity decreasesby 20% relative to the local Mg KLL Auger decays. Spectral analysisreveals that Mg²⁺ ions are preferentially solvated by water;a substantial contribution from ethanol is observed only at high ethanolconcentrations. Molecular dynamics simulations corroborate the experimentalresults, and together they provide quantitative understanding forthe changes in solvation-shell composition, revealing a substantialenrichment of water in the solvation shell relative to the bulk solventcomposition.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1062–1069"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late-Stage Functionalization of a Hexa-peri-Benzocoronene–Fluoranthene Hybrid Influenced by Dynamic Inversion of Helicity","authors":"Lina M. Filla,&nbsp;Alexander R. Krappe,&nbsp;Jacob C. Mayer,&nbsp;Jan M. Sühlo,&nbsp;Larissa S. Eitelhuber,&nbsp;Anja Wiesner,&nbsp;Lukasz Polewski,&nbsp;Ute Resch-Genger,&nbsp;Beate Paulus,&nbsp;Emil J. W. List-Kratochvil,&nbsp;Siegfried Eigler","doi":"10.1021/acsphyschemau.6c00115","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00115","url":null,"abstract":"<p>The functionalizationof a hexa-<em>peri</em>-benzocoronene–fluoranthenehybrid with a K-type bay region is investigated. Bromination proceedsregioselectively at two peripheral positions, which contradicts theelectronic and structural predictions suggesting that substitutionat the K-type bay region should be favored. Computational studiesreveal that the transition state and intermediate energies for allsubstitution positions are comparable, though no substitution in thebay region is observed. To rationalize this unexpected regioselectivity,a model is proposed based on dynamic helical inversion, which preventsthe corresponding Wheland intermediates from being stabilized. Subsequentconversion of the brominated compounds to nitrile derivatives affordscompounds with photoluminescence quantum yields of up to 76% in solution.Organic light-emitting diodes with luminance values of up to 6,500cd·m^–2 are realized due to the effective energylevel alignment by a hole-transport and electron-blocking layer, whichwas not possible with the related nonfunctionalized derivative.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1363–1371"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conformation-Driven Duality in the MBH Proton-Transfer Mechanism: A Dynamic View of Solvent and Entropic Effects","authors":"Patrick R. Batista,&nbsp;João Pedro B. da Silva,&nbsp;Dario Baum,&nbsp;Barbara Kirchner,&nbsp;Cláudio F. Tormena","doi":"10.1021/acsphyschemau.6c00040","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00040","url":null,"abstract":"<p>Understanding howthe solvent structure and molecular conformationdictate reaction mechanisms is essential for advancing organocatalysis.In this work, the solvent effect on the proton-transfer step (rate-determining)of the Morita–Baylis–Hillman (MBH) reaction in a proticmedium was investigated through a combination of <em>ab initio</em> molecular dynamics, well-tempered metadynamics, and on-flow NMRkinetic experiments. The simulations reveal two competing proton-transferpathways involving solvent-assisted and acid–base mechanisms.These pathways have comparable free energy barriers and are drivenmostly by the entropy and conformational preference of the zwitterionicintermediate. Conformational free energy surfaces, combined with NMRanalysis, show that bulky substituents in the electrophilic partnermay cause a steric effect that hinders proton-transfer accessibilityand suppresses MBH adduct formation. These findings establish a directrelationship between conformation and proton-transfer reactivity,highlighting the importance of dynamically addressing the explicitsolvation in the MBH reaction.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1070–1082"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Moments in Single-Atom Alloys: Trends, Mechanisms, and Implications for Tunable Adsorption","authors":"Shengjie Zhang,&nbsp;Collette I. Riviere,&nbsp;Matthew M. Montemore","doi":"10.1021/acsphyschemau.6c00086","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00086","url":null,"abstract":"<p>Single-atom alloyshave proven to have promising and unusual catalytic,chemical, and electronic structure properties. However, the mechanismunderlying their magnetic states and the effect of these states ontheir chemical and catalytic properties are not well understood, despitethe demonstrated importance of magnetism in catalysis. Here, we studythe magnetic states of single-atom alloys consisting of transitionmetals embedded in Cu, Ag, and Au hosts. We find that many single-atomalloys feature strong magnetic moments, associated with large energeticdifferences between spin-polarized and nonspin-polarized states aswell as large effects on adsorption energies. Indeed, the magneticmoment linearly correlates with the effect of the spin on adsorption.The Stoner criterion is generally quite accurate in predicting whethermagnetism occurs. The shift of the d-band center roughly correlateswith the change in the adsorption energy upon inclusion of spin, althoughchanges in the charge on the dopant atom also play a role for Ag-hostsingle-atom alloys. This work opens pathways to leverage magneticproperties in single-atom alloys, including by the static modificationof reactivity, dynamically programming energetics, or local magneticheating at the single-atom site.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1274–1282"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Q-Band Excitation Modulates Exciton–Exciton Annihilation in Tetra(p-Sulfonatophenyl)porphyrin J-Aggregates","authors":"Maria Francesca Cherchi,&nbsp;Teresa Paviglianiti,&nbsp;Dario Baldon,&nbsp;Federico Toffoletti,&nbsp;Elisabetta Collini","doi":"10.1021/acsphyschemau.6c00064","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00064","url":null,"abstract":"<p>The ultrafast photophysics of the Q-band manifold oftetra(<em>p</em>-sulfonatophenyl)porphyrin (H₂TPPS)is investigatedby two-dimensional electronic spectroscopy (2DES) in both its monomericand J-aggregated forms. By selectively exciting different regionsof the Q bands, we uncover strongly excitation-dependent relaxationdynamics in the aggregates. Photoexcitation centered on the lower-energyQ transition leads to pronounced interband coupling and clear signaturesof exciton–exciton annihilation, whereas selective excitationof the higher-energy side of the Q-band manifold limits annihilation.These findings provide new insight into how the mixed Q-band structuregoverns excitation flow in porphyrin aggregates and open avenues forthe rational design of materials with tailored annihilation properties.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1192–1202"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antifungal and Reactive Oxygen Species Response of Saccharomyces cerevisiae to Deep Eutectic Solvents for Bacterial Nanocellulose-Based Eutectogel","authors":"Maurelio Cabo, Jr.,&nbsp;Kwaniyah Tuffour,&nbsp;Dennis LaJeunesse","doi":"10.1021/acsphyschemau.6c00057","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00057","url":null,"abstract":"<p>Antifungal resistanceis an emerging global challenge that requiresnew antimicrobial materials and mechanistic insights. This study aimsto evaluate the antifungal activity and reactive oxygen species (ROS)response of <em>Saccharomyces cerevisiae</em> (TBR1) exposedto imidazole-based deep eutectic solvents (DESs) and ternary DESs(TDESs), including their incorporation into bacterial nanocellulose(BNC) eutectogels. Minimum inhibitory concentration (MIC) resultsshow concentration-dependent inhibition, with DES exhibiting higherantifungal potency than TDES. However, TDES induces significantlygreater ROS production, indicating distinct mechanisms of action.Dead cell assay and scanning electron microscopy (SEM) imaging revealincreased cell death and morphological changes without membrane rupture,supporting oxidative stress-driven intracellular damage. Proton nuclearmagnetic resonance (¹H NMR) metabolite analysis indicatesdisruption of carbohydrate metabolism and energy homeostasis. Diskdiffusion confirms that antifungal activity is primarily driven byimidazole and retained in eutectogel systems, although with reduceddiffusion. Herein, DES and TDES act through membrane interaction,metabolic disruption, and ROS-mediated damage, while BNC integrationenables sustained antimicrobial delivery for potential biomedical,drug delivery system, and wound dressing applications.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1179–1191"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redox-Mediated Reversible C–C Bond Cleavage in Aqueous Electrochemical Systems","authors":"Jong-Hwa Shon,&nbsp;Ruozhu Feng,&nbsp;Ying Chen,&nbsp;Peter S. Rice,&nbsp;Wei Wang","doi":"10.1021/acsphyschemau.6c00053","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00053","url":null,"abstract":"<p>Redox-active organicmolecules provide a versatile platform forapplications such as organocatalysis, electrocatalysis, and energystorage; however, parasitic reactions can yield competing bond-formingpathways that trap the molecule in electrochemically inaccessiblestates, passivating the redox electrochemical reversibility. Reductiveradical coupling exemplifies this challenge. Although carbonyl reductionto an alcohol is a standard chemically reversible process, electrochemicalreduction can induce radical coupling that leads to C–C bondformation, effectively diverting the reaction from the canonical two-electron,two-proton pathway and from electrochemical reversibility. Here, wedemonstrate an electron-abstraction mechanism in which the mediatoractivates chemically reversible, yet electrochemically irreversibleC–C bond scission with an estimated apparent rate constantof 3.54 × 10^–6 M^–1 s^–1 under the tested conditions, which supports the restorationof “net” electrochemical reversibility and bypassesthe large kinetic activation barrier in electrochemical systems. Aflow battery configuration is used to illustrate how this mediatingstrategy enhances energy efficiency in electrochemical systems bybypassing high-kinetic barrier reaction pathways. Spectroscopic analysesdirectly capture both C–C bond formation and dissociation,while density functional theory calculations suggest an electron-abstractionmechanism for C–C bond cleavage. The demonstrated mediated,reversible C–C bond cleavage highlights a mechanistic proof-of-conceptfor overcoming high kinetic activation barriers in otherwise sluggishchemical transformations under electrochemical conditions.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1151–1160"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"pH-Controlled Synthesis of Nb2O5 Nanoparticles with Enhanced Performance for Photodegradation of Organic Pollutants and H2 Production","authors":"Carolina X. J. Silva,&nbsp;Marcela Piassi Bernardo,&nbsp;Ivan José Silva, Jr.,&nbsp;Sheila Cristina Canobre,&nbsp;Osmando F. Lopes","doi":"10.1021/acsphyschemau.5c00132","DOIUrl":"https://doi.org/10.1021/acsphyschemau.5c00132","url":null,"abstract":"<p>Niobium pentoxide(Nb₂O₅) is apromisingphotocatalyst for environmental remediation and solar hydrogen production;however, the role of synthesis parameters in governing its phase compositionand charge-carrier dynamics remains insufficiently understood. Herein,we systematically investigate the effect of synthesis pH (2, 4, and6) on the structural, morphological, electronic, and photocatalyticproperties of Nb₂O₅ nanoparticles prepared viatwo hydrothermal routes. pH variation in Route 1 promotes a phasetransition from pseudohexagonal TT-Nb₂O₅ (pH2) to hydrated Nb₂O₅<em>n</em>H₂O (pH 4–6), accompanied by pronounced morphologicalevolution from nanoneedles to lamellar structures. In contrast, Route2 preserves the TT-Nb₂O₅ phase regardless ofpost-treatment pH, highlighting its structural stability. In organicpollutant degradation, all samples were active toward Rhodamine Band amiloride, where mechanistic studies revealed a hole-dominatedoxidation pathway with secondary involvement of superoxide radicals.Hydrated Nb₂O₅·<em>n</em>H₂O phases exhibited strong adsorption capacity, whereas TT-Nb₂O₅ showed higher intrinsic photocatalytic efficiency.Stability tests confirmed sustained activity over four cycles. TT-Nb₂O₅ materials also exhibited superior charge-transferproperties and were active in H₂ evolution, achieving upto 4104.5 μmol g^–1 after 8 h (Nb₂O₅-AP2). Optimization of Pt loading revealed an optimalcocatalyst content of 0.5 wt %, while long-term assays confirmed stableH₂ production over 24 h of operation. Photoluminescenceresults indicated that recombination suppression contributes to performanceenhancement but does not solely govern activity. These findings demonstratethat synthesis pH governs phase formation, surface chemistry, andcharge-carrier dynamics in Nb₂O₅, providingfundamental insights into the rational design of niobium-based photocatalyststailored for integrated environmental and energy applications.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1018–1030"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Investigation of the Effect of Transition Metal Coordination in Bimetallic Uranylpyridine-Dicarboxylate Complexes","authors":"Keerthan R. Rao,&nbsp;Heather J. Culbertson,&nbsp;Shuxiang Zhou,&nbsp;Peter C. Burns,&nbsp;Tori Z. Forbes,&nbsp;Ashini S. Jayasinghe","doi":"10.1021/acsphyschemau.6c00096","DOIUrl":"https://doi.org/10.1021/acsphyschemau.6c00096","url":null,"abstract":"<p>Understanding howsecondary metal coordination perturbs uranylelectronic structure is important for developing structure-propertyrelationships in actinide-containing materials relevant to separations,waste management, and environmental chemistry. In this work, periodicand cluster density functional theory calculations were used to investigatethe structural, electronic, and vibrational properties of monometallicU-2,6-pyridinedicarboxylic acid (PDC) and heterometallic U-PDC-TMcomplexes (TM = Fe, Co, Ni, Cu, and Zn). Incorporating transitionmetal (TM) changes the valence-band electronic structure of the U-PDC-TMframework due to TM <em>d</em> and ligand O 2<em>p</em> contributions near the band edge and reduces the bandgap acrossmost of the series. The nature of these states is supported by thefrontier molecular orbital diagrams constructed from the cluster models.Charge redistribution is observed along the TM octahedral unit andthe bridging ligand framework rather than direct interaction withthe uranyl center. Simulated Raman vibrational modes agree reasonablywell with experiments for the ligand ring bending and breathing modes,although subtle TM-dependent changes in the uranyl stretching modewere not consistently captured across the full series. The phononmodes show a blue shift in the uranyl symmetric stretch consistentwith experiments when Ni is incorporated into the U-PDC structure,indicating U≡O bond strengthening. The change in the partialcharges on the U center confirms a small electron density accumulationdue to the presence of TMs. Our results show that incorporating secondaryTM provides a viable strategy for tuning the electronic propertiesof uranyl coordination complexes through indirect ligand-mediatedcoupling.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":"6 5","pages":"1308–1319"},"PeriodicalIF":4.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}