Yu Gao,Erfan Shahroudi,Stefan Bouts,Yonghui Fan,Yin Li,Peeranat Chaipornchalerm,Junbu Wang,Konstantin Klementiev,Nikolay Kosinov,Emiel J. M. Hensen
Cu-based ternary catalysts often outperform their binary counterparts in the hydrogenation of CO2 to methanol. Unraveling the underlying synergistic effects among multiple components remains challenging and requires comprehensive operando characterization. In this study, we present a detailed investigation into the synergistic Cu−Zn−Zr interactions in inverse ZnZrOx/Cu catalysts, which show strong promise for enhancing the synthesis of methanol from CO2. In situ X-ray diffraction revealed that ZrO2 clusters effectively stabilize Cu nanoparticles against sintering during the H2 reduction. Operando X-ray absorption spectroscopy at the Cu, Zn, and Zr K-edges demonstrated that the enhanced reducibility of Zn and Zr species arises from synergistic Cu–Zn–Zr interactions. Upon H2 reduction, partially reduced ZrO2 facilitated CO2 adsorption and activation. Initially dispersed Zn2+ species were partially transformed into the CuZn alloy, which remained stable under reaction conditions. Notably, the CuZn alloy significantly enhanced the hydrogenation of key formate reaction intermediates to methanol. Moreover, Zn incorporation in Cu inhibited methanol decomposition to CO. The combined effects of efficient H2 activation on highly dispersed metallic Cu, enhanced CO2 activation by reduced ZrO2 clusters, and rapid formate hydrogenation facilitated by the CuZn alloy rendered inverse ZnZrOx/Cu catalysts superior in methanol formation rates as compared to inverse ZnOx/Cu, ZrOx/Cu catalysts, a commercial CuZnAl catalyst, and previously reported CuZnZr catalysts.
{"title":"Component-Specific Functions of Cu, Zn, and Zr in Inverse ZnZrOx/Cu Catalysts for CO2 Hydrogenation to Methanol","authors":"Yu Gao,Erfan Shahroudi,Stefan Bouts,Yonghui Fan,Yin Li,Peeranat Chaipornchalerm,Junbu Wang,Konstantin Klementiev,Nikolay Kosinov,Emiel J. M. Hensen","doi":"10.1021/jacs.5c19915","DOIUrl":"https://doi.org/10.1021/jacs.5c19915","url":null,"abstract":"Cu-based ternary catalysts often outperform their binary counterparts in the hydrogenation of CO2 to methanol. Unraveling the underlying synergistic effects among multiple components remains challenging and requires comprehensive operando characterization. In this study, we present a detailed investigation into the synergistic Cu−Zn−Zr interactions in inverse ZnZrOx/Cu catalysts, which show strong promise for enhancing the synthesis of methanol from CO2. In situ X-ray diffraction revealed that ZrO2 clusters effectively stabilize Cu nanoparticles against sintering during the H2 reduction. Operando X-ray absorption spectroscopy at the Cu, Zn, and Zr K-edges demonstrated that the enhanced reducibility of Zn and Zr species arises from synergistic Cu–Zn–Zr interactions. Upon H2 reduction, partially reduced ZrO2 facilitated CO2 adsorption and activation. Initially dispersed Zn2+ species were partially transformed into the CuZn alloy, which remained stable under reaction conditions. Notably, the CuZn alloy significantly enhanced the hydrogenation of key formate reaction intermediates to methanol. Moreover, Zn incorporation in Cu inhibited methanol decomposition to CO. The combined effects of efficient H2 activation on highly dispersed metallic Cu, enhanced CO2 activation by reduced ZrO2 clusters, and rapid formate hydrogenation facilitated by the CuZn alloy rendered inverse ZnZrOx/Cu catalysts superior in methanol formation rates as compared to inverse ZnOx/Cu, ZrOx/Cu catalysts, a commercial CuZnAl catalyst, and previously reported CuZnZr catalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"176 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138815","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}
Emily Sakamoto-Rablah,Jordan Bye,Arghya Modak,Andrew Hooker,Shahid Uddin,Jennifer J. McManus
In Figure 2(a) of the published article, the units on the y-axis were incorrectly given as “mol g–1”. The correct units should be “μmol g–1”. The complete, corrected Figure 2 is shown below. This correction does not affect the data, analysis or conclusions of the paper. Figure 2. SLS data plotted as a Debye plot. Straight lines are linear fits to data with slopes equal to the second virial coefficient B22. (b) Diffusion data measured by dynamic light scattering (DLS). Straight lines show fits to the data with the slope equal to interaction parameter kD. (c) Relationship between the interaction parameter and second virial coefficient for ImmTAC1 and lysozyme. Data for lysozyme is reproduced from Muschol and Rosenberger.15 Inset shows the relationship between the measured hydrodynamic radius and molecular weight for ImmTAC1 along with the expected relationship (dashed line) calculated from the theory (eq 17). (d) Hydrodynamic function calculated using eq 12 as a function of concentration. This article has not yet been cited by other publications.
{"title":"Correction to “Synthetic T-Cell Receptor-like Protein Behaves as a Janus Particle in Solution”","authors":"Emily Sakamoto-Rablah,Jordan Bye,Arghya Modak,Andrew Hooker,Shahid Uddin,Jennifer J. McManus","doi":"10.1021/jacs.6c00896","DOIUrl":"https://doi.org/10.1021/jacs.6c00896","url":null,"abstract":"In Figure 2(a) of the published article, the units on the <i>y</i>-axis were incorrectly given as “mol g<sup>–1</sup>”. The correct units should be “μmol g<sup>–1</sup>”. The complete, corrected Figure 2 is shown below. This correction does not affect the data, analysis or conclusions of the paper. Figure 2. SLS data plotted as a Debye plot. Straight lines are linear fits to data with slopes equal to the second virial coefficient <i>B</i><sub>22</sub>. (b) Diffusion data measured by dynamic light scattering (DLS). Straight lines show fits to the data with the slope equal to interaction parameter <i>k</i><sub>D</sub>. (c) Relationship between the interaction parameter and second virial coefficient for ImmTAC1 and lysozyme. Data for lysozyme is reproduced from Muschol and Rosenberger.<sup>15</sup> Inset shows the relationship between the measured hydrodynamic radius and molecular weight for ImmTAC1 along with the expected relationship (dashed line) calculated from the theory (eq 17). (d) Hydrodynamic function calculated using eq 12 as a function of concentration. This article has not yet been cited by other publications.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"5 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138865","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}
Spin polarization governs the kinetics of multielectron water oxidation, yet benchmark catalysts like IrO2 lack intrinsic ferromagnetism at ambient temperature, precluding spin control. Here, we exploit the interfacial Dzyaloshinskii–Moriya interaction (DMI) in Co/IrO2 bilayers to induce spin-polarized states in the surface IrO2. This DMI-driven spin polarization boosts intrinsic oxygen evolution reaction activity by 1 order of magnitude, achieving a turnover frequency of 4.17 s–1 at 300 mV overpotential. Ferromagnetic resonance spectroscopy quantifies strong interfacial spin polarization via a 100% increase in the Gilbert damping. Spin-polarized DFT shows that DMI stabilizes a ferromagnetic ground state in IrO2 and reveals that spin ordering alters the adsorption configurations and lowers reaction barriers for *OH dehydrogenation and O–O coupling. Inserting a Cu spacer eliminates DMI, quenching both magnetism and catalytic enhancement. Our results establish interfacial DMI as a general strategy to activate hidden spin states in nonmagnetic oxides, offering a new route to surpass the activity limits in water-oxidation catalysis.
{"title":"Water Oxidation Promoted by Proximity-Induced Magnetism under Dzyaloshinskii–Moriya Interaction","authors":"Xiao Ren,Lei Tao,Tianze Wu,Rui Sun,Xiaotian Zhao,Xingjie Peng,Wu Zhou,Ding Ma,Shixuan Du,Zhichuan J. Xu","doi":"10.1021/jacs.5c17778","DOIUrl":"https://doi.org/10.1021/jacs.5c17778","url":null,"abstract":"Spin polarization governs the kinetics of multielectron water oxidation, yet benchmark catalysts like IrO2 lack intrinsic ferromagnetism at ambient temperature, precluding spin control. Here, we exploit the interfacial Dzyaloshinskii–Moriya interaction (DMI) in Co/IrO2 bilayers to induce spin-polarized states in the surface IrO2. This DMI-driven spin polarization boosts intrinsic oxygen evolution reaction activity by 1 order of magnitude, achieving a turnover frequency of 4.17 s–1 at 300 mV overpotential. Ferromagnetic resonance spectroscopy quantifies strong interfacial spin polarization via a 100% increase in the Gilbert damping. Spin-polarized DFT shows that DMI stabilizes a ferromagnetic ground state in IrO2 and reveals that spin ordering alters the adsorption configurations and lowers reaction barriers for *OH dehydrogenation and O–O coupling. Inserting a Cu spacer eliminates DMI, quenching both magnetism and catalytic enhancement. Our results establish interfacial DMI as a general strategy to activate hidden spin states in nonmagnetic oxides, offering a new route to surpass the activity limits in water-oxidation catalysis.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"39 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138812","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}
Bereket L. Zekarias,Luis Pablo Arriaga Gonzalez,Olivia A. De Luca,Andrew Kelly,Kevin Qian,Eric A. Riesel,Connor Orrison,Dong Hee Son,Evripidis Michail,Matthew Y. Sfeir,Rachel N. Austin,Jonathan S. Owen,Makeda A. Tekle-Smith
Mn2+-doped CdS/ZnS quantum dots, in which surface stearate ligands are replaced with ligands that form ion pairs, are stable photocatalysts capable of reducing a variety of aryl chloride substrates, defluorinating fluorinated aromatic compounds, and facilitating the formation of new C–C bonds. Enhanced activity of the electrostatically stabilized quantum dot dispersions in polar solutions is observed at very low catalyst loadings (0.0005 mol %). The full scope of the reactions studied points to the importance of engineering quantum dot surface chemistry to control the reactivity afforded by hot electrons generated by multiphoton absorption and Auger upconversion.
{"title":"Engineering Mn2+-Doped CdS/ZnS Quantum Dot Surfaces to Control Auger Upconversion Photocatalysis","authors":"Bereket L. Zekarias,Luis Pablo Arriaga Gonzalez,Olivia A. De Luca,Andrew Kelly,Kevin Qian,Eric A. Riesel,Connor Orrison,Dong Hee Son,Evripidis Michail,Matthew Y. Sfeir,Rachel N. Austin,Jonathan S. Owen,Makeda A. Tekle-Smith","doi":"10.1021/jacs.5c21777","DOIUrl":"https://doi.org/10.1021/jacs.5c21777","url":null,"abstract":"Mn2+-doped CdS/ZnS quantum dots, in which surface stearate ligands are replaced with ligands that form ion pairs, are stable photocatalysts capable of reducing a variety of aryl chloride substrates, defluorinating fluorinated aromatic compounds, and facilitating the formation of new C–C bonds. Enhanced activity of the electrostatically stabilized quantum dot dispersions in polar solutions is observed at very low catalyst loadings (0.0005 mol %). The full scope of the reactions studied points to the importance of engineering quantum dot surface chemistry to control the reactivity afforded by hot electrons generated by multiphoton absorption and Auger upconversion.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"45 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138818","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}
Henrik R. Wilke,Marlene Fadel,Kacper J. Patej,Jan P. Prohaska,Jonathan Kastner,Veronika Avramenko,Oscar Garcia Gonzalez,Rüveyda Bal,Matteo C. Amberg,Jameel Ahmad,Nima Nasiri,Tobias K. Jenny,Erick M. Carreira
We report the first total synthesis of (±)-dhilirolide U, a highly oxidized meroterpenoid featuring a densely functionalized 6/6/6/5/5-pentacyclic skeleton. Central to the strategy are a MnIII-mediated cyclization sequence and a Payne-type rearrangement cascade, which together forge a bicyclo[3.2.1]octane fused to a γ-lactone─the defining motif of the dhilirolide natural product family. Both transformations proceed in high yields and with excellent diastereocontrol. Intramolecular Ni-catalyzed conjugate addition was leveraged to install the vicinal quaternary carbon centers. This transformation set the stage for construction of the tetrahydroisochromenone subunit and completion of (±)-dhilirolide U. The reported route to the highly decorated bicyclo[3.2.1]octane provides a blueprint to access the diverse family that are the complex dhilirolide meroterpenoids.
{"title":"Total Synthesis of (±)-Dhilirolide U","authors":"Henrik R. Wilke,Marlene Fadel,Kacper J. Patej,Jan P. Prohaska,Jonathan Kastner,Veronika Avramenko,Oscar Garcia Gonzalez,Rüveyda Bal,Matteo C. Amberg,Jameel Ahmad,Nima Nasiri,Tobias K. Jenny,Erick M. Carreira","doi":"10.1021/jacs.5c22734","DOIUrl":"https://doi.org/10.1021/jacs.5c22734","url":null,"abstract":"We report the first total synthesis of (±)-dhilirolide U, a highly oxidized meroterpenoid featuring a densely functionalized 6/6/6/5/5-pentacyclic skeleton. Central to the strategy are a MnIII-mediated cyclization sequence and a Payne-type rearrangement cascade, which together forge a bicyclo[3.2.1]octane fused to a γ-lactone─the defining motif of the dhilirolide natural product family. Both transformations proceed in high yields and with excellent diastereocontrol. Intramolecular Ni-catalyzed conjugate addition was leveraged to install the vicinal quaternary carbon centers. This transformation set the stage for construction of the tetrahydroisochromenone subunit and completion of (±)-dhilirolide U. The reported route to the highly decorated bicyclo[3.2.1]octane provides a blueprint to access the diverse family that are the complex dhilirolide meroterpenoids.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"5 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138819","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}
Ferroptosis is an Fe2+-dependent and lipid peroxidation-mediated regulated cell death. Its early detection is critical for diagnosis and timely intervention. Lipid hydrogen abstraction is the initiation step of the “lipid peroxidation-ferroptosis” cascade and an ideal target for early detection of ferroptosis. We developed the first set of fluorogenic probes for lipid H-abstraction, i.e., LHA585 for red, LHA675 for deep-red, and LHA930 for near-infrared. The key to their design is the use of 4-phenyl-3-methylbut-2-enyl, a close mimic of the polyunsaturated lipid, to specifically detect the highly oxidative radicals involved in ferroptosis. Notably, LHA585 yielded a fluorescence turn-on ca. 8 h earlier than the current gold-standard probe in an in vitro OGD/R model, highlighting its superiority for early detection of ferroptosis. While LHA585/675 is intended for in vitro studies, LHA930 was feasible for in vivo ferroptosis detection. Collectively, these findings establish LHAs as a robust advance for ferroptosis sensing, enabling in-depth mechanistic studies of lipid-peroxidation-driven cell death.
{"title":"Early Ferroptosis Detection Targeting Lipid Hydrogen Abstraction","authors":"Cankun Li,Cheng Yao,Ruiqi Su,Yanyan Deng,Chunchun Jiang,Yuyang Zhang,Jiamu Wei,Lili Li,Linyan Huang,Yubo Lin,Guangbo Ge,Suhua Qi,Xuhong Qian,Xiao Luo,Youjun Yang","doi":"10.1021/jacs.5c17084","DOIUrl":"https://doi.org/10.1021/jacs.5c17084","url":null,"abstract":"Ferroptosis is an Fe2+-dependent and lipid peroxidation-mediated regulated cell death. Its early detection is critical for diagnosis and timely intervention. Lipid hydrogen abstraction is the initiation step of the “lipid peroxidation-ferroptosis” cascade and an ideal target for early detection of ferroptosis. We developed the first set of fluorogenic probes for lipid H-abstraction, i.e., LHA585 for red, LHA675 for deep-red, and LHA930 for near-infrared. The key to their design is the use of 4-phenyl-3-methylbut-2-enyl, a close mimic of the polyunsaturated lipid, to specifically detect the highly oxidative radicals involved in ferroptosis. Notably, LHA585 yielded a fluorescence turn-on ca. 8 h earlier than the current gold-standard probe in an in vitro OGD/R model, highlighting its superiority for early detection of ferroptosis. While LHA585/675 is intended for in vitro studies, LHA930 was feasible for in vivo ferroptosis detection. Collectively, these findings establish LHAs as a robust advance for ferroptosis sensing, enabling in-depth mechanistic studies of lipid-peroxidation-driven cell death.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"161 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138816","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}
The development of chemoselective reduction methods for conjugated carbonyl compounds remains a long-standing challenge in organic synthesis. Here we introduce a metal-free organocatalytic strategy that accomplishes the deoxygenative reduction of α,β-unsaturated ketones through the distinct FLP-type reactivity of N–heterocyclic nitrenium (NHN) salts and their N–H triazane derivatives. The protocol operates efficiently with low catalyst loadings, accommodates diverse substrates, and can be scaled to gram quantities. Key to the selectivity is the transient use of water or methanol as a protecting agent for the C═C bond, enabling targeted carbonyl reduction by hydride transfer from triazane. Combined experimental and computational studies elucidate the origins of chemoselectivity and reveal how hydride affinity and ion pairing distinguish NHN-based catalysis from B(C6F5)3-mediated reductions. These findings expand the synthetic toolbox for selective enone deoxygenation and establish nitrenium FLP chemistry as a promising platform for the design of new, metal-free reduction processes.
{"title":"Organocatalytic Deoxygenative Reduction of α,β-Unsaturated Ketones","authors":"Deepak Ranolia,Aleksandr Koronatov,Guy Israeli,Alexander Kaushansky,Natalia Fridman,Mark Gandelman","doi":"10.1021/jacs.5c18403","DOIUrl":"https://doi.org/10.1021/jacs.5c18403","url":null,"abstract":"The development of chemoselective reduction methods for conjugated carbonyl compounds remains a long-standing challenge in organic synthesis. Here we introduce a metal-free organocatalytic strategy that accomplishes the deoxygenative reduction of α,β-unsaturated ketones through the distinct FLP-type reactivity of N–heterocyclic nitrenium (NHN) salts and their N–H triazane derivatives. The protocol operates efficiently with low catalyst loadings, accommodates diverse substrates, and can be scaled to gram quantities. Key to the selectivity is the transient use of water or methanol as a protecting agent for the C═C bond, enabling targeted carbonyl reduction by hydride transfer from triazane. Combined experimental and computational studies elucidate the origins of chemoselectivity and reveal how hydride affinity and ion pairing distinguish NHN-based catalysis from B(C6F5)3-mediated reductions. These findings expand the synthetic toolbox for selective enone deoxygenation and establish nitrenium FLP chemistry as a promising platform for the design of new, metal-free reduction processes.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"18 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138814","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}
Sonja M. Biebl,Jonas N. Lienert,Adrian J. Müller,Markus Ströbele,Andreas Dreuw,Josef Wachtveitl,Holger F. Bettinger
Derivatives of 1,2-dihydro-1,2-azaborinines generally undergo selective photochemical electrocyclic ring-closure reactions to the corresponding Dewar isomers (2-aza-3-borabicyclo[2.2.0]hex-5-ene). Depending on the substitution pattern, these photoreactions can also yield benzvalene (3-aza-4-boratricyclo[3.1.0.02.6]hexane) analogues. Here, we report the synthesis of 1,2,3,5-tetrasubstituted dihydroazaborinines by transition-metal-catalyzed late-stage functionalization and the investigation of their photophysical and photochemical properties using transient absorption spectroscopy. The introduction of aryl groups at the 3- and 5-positions induces a pronounced bathochromic shift of the absorption maximum. Under broad-spectrum irradiation (280–400 nm), quantitative conversion to the benzvalene isomer can be achieved. The initial photoisomerization proceeds via excitation to the short-lived singlet excited state (S1) yielding the Dewar isomer, whereas the subsequent conversion of this intermediate occurs through a long-lived excited state. Notably, the second isomerization step is accompanied by an interchange of the carbons C3 and C4. Once formed, the benzvalene isomers exhibit exceptional thermal stability. Cycloreversion to the Dewar isomer and even to the dihydroazaborinine structure can be triggered photochemically through targeted excitation and during both processes the substituents return to the C3 and C5 positions. The thermal cycloreversion of the benzvalene isomer can yield either the educt BN-benzene isomer (1,2,3,5-substitued) or its 1,2,4,5-substituted isomer. Computational studies revealed a stepwise mechanism for the thermal back reaction reforming the educt, while a concerted, energetically less-favorable pathway leads to the 1,2,4,5-substituted analogue.
{"title":"Switching Shapes: Reversible Three Species Photoisomerization of Substituted 1,2-Dihydro-1,2-azaborinines","authors":"Sonja M. Biebl,Jonas N. Lienert,Adrian J. Müller,Markus Ströbele,Andreas Dreuw,Josef Wachtveitl,Holger F. Bettinger","doi":"10.1021/jacs.5c20667","DOIUrl":"https://doi.org/10.1021/jacs.5c20667","url":null,"abstract":"Derivatives of 1,2-dihydro-1,2-azaborinines generally undergo selective photochemical electrocyclic ring-closure reactions to the corresponding Dewar isomers (2-aza-3-borabicyclo[2.2.0]hex-5-ene). Depending on the substitution pattern, these photoreactions can also yield benzvalene (3-aza-4-boratricyclo[3.1.0.02.6]hexane) analogues. Here, we report the synthesis of 1,2,3,5-tetrasubstituted dihydroazaborinines by transition-metal-catalyzed late-stage functionalization and the investigation of their photophysical and photochemical properties using transient absorption spectroscopy. The introduction of aryl groups at the 3- and 5-positions induces a pronounced bathochromic shift of the absorption maximum. Under broad-spectrum irradiation (280–400 nm), quantitative conversion to the benzvalene isomer can be achieved. The initial photoisomerization proceeds via excitation to the short-lived singlet excited state (S1) yielding the Dewar isomer, whereas the subsequent conversion of this intermediate occurs through a long-lived excited state. Notably, the second isomerization step is accompanied by an interchange of the carbons C3 and C4. Once formed, the benzvalene isomers exhibit exceptional thermal stability. Cycloreversion to the Dewar isomer and even to the dihydroazaborinine structure can be triggered photochemically through targeted excitation and during both processes the substituents return to the C3 and C5 positions. The thermal cycloreversion of the benzvalene isomer can yield either the educt BN-benzene isomer (1,2,3,5-substitued) or its 1,2,4,5-substituted isomer. Computational studies revealed a stepwise mechanism for the thermal back reaction reforming the educt, while a concerted, energetically less-favorable pathway leads to the 1,2,4,5-substituted analogue.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"5 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139028","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}
Minjie Zhao,Daviel Gómez,Vlad Martin-Diaconescu,Laura Simonelli,Miguel Lopez-Haro,Jose Juan Calvino,Avelino Corma,Patricia Concepción
This work presents a strategy to control not only the distance and proximity of active sites at the atomic or nanoscale but also the nature of sites in zeolite-based catalysts, promoting the coupling rate of surface intermediate species and accordingly the formation rate of dimethyl ether (DME) by a direct CO2 hydrogenation path. We use a one-pot synthesis strategy and a thermal-induced detachment process of framework elements, such as Ga3+ ions, to stabilize PdGa alloys and Ga+ sites in close proximity to Brønsted acid sites under reductive conditions. Using this strategy, a production of oxygenates of up to 42,864 gMeOH+DME·kgPd–1·h–1 at 45 bar, 260 °C, and WHSV = 15,000 mL·gcat–1·h–1, is obtained with 80% selectivity to oxygenated (19% methanol/61% DME), outperforming the most active Pd-based CO2 hydrogenation catalysts in the literature. Time-resolved kinetic studies, in situ X-ray adsorption, and in situ and operando IR offer strong proof of the key role of isolated Ga+ Lewis acid sites in close proximity to Brønsted acid sites in stabilizing monoformate intermediate species and facilitating the direct production of DME. Finally, this work highlights the key role of the zeolite in metal confinement, conferring excellent stability, oxidation resistance, hydrophilicity, and close proximity of active sites together with the stabilization of low-coordinated Lewis acid sites.
{"title":"Decoding the Role of Isolated Ga+ in PdGa@MFI Catalyst Promoting a Direct CO2 Hydrogenation Path to DME","authors":"Minjie Zhao,Daviel Gómez,Vlad Martin-Diaconescu,Laura Simonelli,Miguel Lopez-Haro,Jose Juan Calvino,Avelino Corma,Patricia Concepción","doi":"10.1021/jacs.5c20643","DOIUrl":"https://doi.org/10.1021/jacs.5c20643","url":null,"abstract":"This work presents a strategy to control not only the distance and proximity of active sites at the atomic or nanoscale but also the nature of sites in zeolite-based catalysts, promoting the coupling rate of surface intermediate species and accordingly the formation rate of dimethyl ether (DME) by a direct CO2 hydrogenation path. We use a one-pot synthesis strategy and a thermal-induced detachment process of framework elements, such as Ga3+ ions, to stabilize PdGa alloys and Ga+ sites in close proximity to Brønsted acid sites under reductive conditions. Using this strategy, a production of oxygenates of up to 42,864 gMeOH+DME·kgPd–1·h–1 at 45 bar, 260 °C, and WHSV = 15,000 mL·gcat–1·h–1, is obtained with 80% selectivity to oxygenated (19% methanol/61% DME), outperforming the most active Pd-based CO2 hydrogenation catalysts in the literature. Time-resolved kinetic studies, in situ X-ray adsorption, and in situ and operando IR offer strong proof of the key role of isolated Ga+ Lewis acid sites in close proximity to Brønsted acid sites in stabilizing monoformate intermediate species and facilitating the direct production of DME. Finally, this work highlights the key role of the zeolite in metal confinement, conferring excellent stability, oxidation resistance, hydrophilicity, and close proximity of active sites together with the stabilization of low-coordinated Lewis acid sites.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"90 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138811","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}
On-surface synthesis has revolutionized the construction of functional nanostructures. Thus far, however, the concept of polymer tacticity has remained unexplored in this context. Tacticity impacts polymer properties, which in turn governs polymer applications. An all-syn arrangement of substituents in isotactic polymers, for instance, may lead to highly crystalline, high-strength materials. Thus, specialized methods have been developed involving chiral catalysts or ligands to control polymer tacticity. In this work, we demonstrate that two-dimensional surface confinement of on-surface polymerization can be combined with preorganization of monomers to synthesize isotactic polymer chains in the absence of a chiral auxiliary. To establish the concept, we synthesized a corannulene-substituted terphenylene monomer capable of C–H···π bonding, aromatic stacking, and van der Waals interactions. The weak intermolecular interactions steer the monomer into organized double strands, with the corannulene substituents oriented only on one side of the strand on Ag(111). A subsequent Ullmann polymerization of the self-assembled monomers leads to the formation of double-stranded isotactic polyphenylenes. The stereoregularity further allows the duplex to arrange into higher-order crystalline domains. Finally, the synthetic polymer duplex can be mechanically unzipped into individual isotactic polymer chains through scanning tunneling microscopy tip manipulation.
{"title":"On-Surface Synthesis of Isotactic Double-Stranded Corannulene Polymers Steered by Hierarchical Supramolecular Self-Assembly","authors":"Haolin Dong,Zhongbo Zhang,Zhifang Wang,Yan Guo,Xinxin Huang,Qiang Huang,Jonas Björk,Johanna Rosen,Mihaiela C. Stuparu,Kaifeng Niu,Lifeng Chi,Qigang Zhong","doi":"10.1021/jacs.5c16884","DOIUrl":"https://doi.org/10.1021/jacs.5c16884","url":null,"abstract":"On-surface synthesis has revolutionized the construction of functional nanostructures. Thus far, however, the concept of polymer tacticity has remained unexplored in this context. Tacticity impacts polymer properties, which in turn governs polymer applications. An all-syn arrangement of substituents in isotactic polymers, for instance, may lead to highly crystalline, high-strength materials. Thus, specialized methods have been developed involving chiral catalysts or ligands to control polymer tacticity. In this work, we demonstrate that two-dimensional surface confinement of on-surface polymerization can be combined with preorganization of monomers to synthesize isotactic polymer chains in the absence of a chiral auxiliary. To establish the concept, we synthesized a corannulene-substituted terphenylene monomer capable of C–H···π bonding, aromatic stacking, and van der Waals interactions. The weak intermolecular interactions steer the monomer into organized double strands, with the corannulene substituents oriented only on one side of the strand on Ag(111). A subsequent Ullmann polymerization of the self-assembled monomers leads to the formation of double-stranded isotactic polyphenylenes. The stereoregularity further allows the duplex to arrange into higher-order crystalline domains. Finally, the synthetic polymer duplex can be mechanically unzipped into individual isotactic polymer chains through scanning tunneling microscopy tip manipulation.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138813","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}
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