Hongye Wang, Shiyu Zhang, Shengrui Xia, Juanhua Zhou, Yang Liu
Endowing the electrochemiluminescence (ECL) imaging technique with three-dimensional (3D) resolution to investigate specimens at varying axial depths poses a challenging yet significant objective. Herein, a “confocal” 3D ECL imaging method was developed using luminol as the ECL probe, in which the excited luminophore was formed in the vicinity of electrode surface through homogeneous chemical reactions between oppositely diffusing ECL precursors, luminol diazaquinone intermediate (L) and hydrogen peroxide (H2O2), confining the ECL emission in a thin plane (ECL focal plane) parallel to the electrode surface at their intersection. The regulating ability of electrochemical method on the reaction fluxes of L and H2O2 was validated, realizing in-situ regulation of the axial location of the ECL focal plane from 0 to 63 μm. Leveraging the optical sectioning capability of the ECL focal plane, the “confocal” 3D ECL imaging method was applied to bioimaging, from cells to tissue sections. It revealed cellular morphology changes during cell polarity establishment and the heterogeneous distribution of complex tubule structure in kidney tissue sections. The optical sectioning capability of “confocal” 3D ECL imaging makes it a powerful tool for studying complex biological samples.
{"title":"In-Situ “Confocal” Electrochemiluminescence 3D Imaging: From Cell to Tissue Section","authors":"Hongye Wang, Shiyu Zhang, Shengrui Xia, Juanhua Zhou, Yang Liu","doi":"10.1002/anie.202503594","DOIUrl":"https://doi.org/10.1002/anie.202503594","url":null,"abstract":"Endowing the electrochemiluminescence (ECL) imaging technique with three-dimensional (3D) resolution to investigate specimens at varying axial depths poses a challenging yet significant objective. Herein, a “confocal” 3D ECL imaging method was developed using luminol as the ECL probe, in which the excited luminophore was formed in the vicinity of electrode surface through homogeneous chemical reactions between oppositely diffusing ECL precursors, luminol diazaquinone intermediate (L) and hydrogen peroxide (H2O2), confining the ECL emission in a thin plane (ECL focal plane) parallel to the electrode surface at their intersection. The regulating ability of electrochemical method on the reaction fluxes of L and H2O2 was validated, realizing in-situ regulation of the axial location of the ECL focal plane from 0 to 63 μm. Leveraging the optical sectioning capability of the ECL focal plane, the “confocal” 3D ECL imaging method was applied to bioimaging, from cells to tissue sections. It revealed cellular morphology changes during cell polarity establishment and the heterogeneous distribution of complex tubule structure in kidney tissue sections. The optical sectioning capability of “confocal” 3D ECL imaging makes it a powerful tool for studying complex biological samples.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"3 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862545","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}
Fenglin Hong, L. Anders Hammarback, Yihong Wang, Craig M. Robertson, John Bower
A cationic Ir(I)-complex modified with the chiral diphosphine DM-SEGPHOS mediates the hydroalkylation of diverse α-methyl styrenes with N-aryl glycine derivatives. The processes occur with complete branched selectivity and high enantioselectivity. Styrenes possessing higher α-alkyl substituents also participate to provide the targets with moderate to excellent levels of diastereoselectivity. The products are readily advanced to β-quaternary α-amino acids that are inaccessible or cumbersome to access by other means. In broader terms, the study demonstrates how catalyst controlled C-H additions across alkenes can be used to execute the byproduct free construction of contiguous acyclic trisubstituted and quaternary centers.
{"title":"β-Quaternary α-Amino Acids via Iridium-Catalyzed Branched and Enantioselective Hydroalkylation of 1,1-Disubstituted Styrenes","authors":"Fenglin Hong, L. Anders Hammarback, Yihong Wang, Craig M. Robertson, John Bower","doi":"10.1002/anie.202504477","DOIUrl":"https://doi.org/10.1002/anie.202504477","url":null,"abstract":"A cationic Ir(I)-complex modified with the chiral diphosphine DM-SEGPHOS mediates the hydroalkylation of diverse α-methyl styrenes with N-aryl glycine derivatives. The processes occur with complete branched selectivity and high enantioselectivity. Styrenes possessing higher α-alkyl substituents also participate to provide the targets with moderate to excellent levels of diastereoselectivity. The products are readily advanced to β-quaternary α-amino acids that are inaccessible or cumbersome to access by other means. In broader terms, the study demonstrates how catalyst controlled C-H additions across alkenes can be used to execute the byproduct free construction of contiguous acyclic trisubstituted and quaternary centers.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"71 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862546","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}
Recent years have witnessed an increasing application of machine learning (ML) in reaction development. These ML methods, in general, require huge training set examples. The published literature has large amounts of data, but there are modelling challenges due to the sparse nature of these datasets. Here we report a meta-learning workflow that can utilize the literature-mined data and return accurate predictions with limited data. A literature dataset comprising of over 12,000 transition metal catalyzed asymmetric hydrogenation of olefins (AHO) is chosen to demonstrate the utility of our protocol. A meta-model is trained in a binary classification setting to identify highly enantioselective AHO reactions. Two Bayesian meta-learning approaches are considered, namely, deep kernel transfer (DKT) and adaptive deep kernel fitting (ADKF). Both these methods returned better predictions compared to prototypical network. The single-task methods such as random forest and graph neural network performed worse than meta-learning methods. Additionally, we propose another meta-learning approach called ADKF-prior that is shown to further improve the performance in low-data settings. Our meta-learning workflow can be utilized to build a pretrained meta-model for any reaction of interest, which can then be useful to predict the outcome of new but related reactions in a few-shot manner.
{"title":"Bayesian Meta-Learning for Few-Shot Reaction Outcome Prediction of Asymmetric Hydrogenation of Olefins","authors":"Sukriti Singh, José Miguel Hernández-Lobato","doi":"10.1002/anie.202503821","DOIUrl":"https://doi.org/10.1002/anie.202503821","url":null,"abstract":"Recent years have witnessed an increasing application of machine learning (ML) in reaction development. These ML methods, in general, require huge training set examples. The published literature has large amounts of data, but there are modelling challenges due to the sparse nature of these datasets. Here we report a meta-learning workflow that can utilize the literature-mined data and return accurate predictions with limited data. A literature dataset comprising of over 12,000 transition metal catalyzed asymmetric hydrogenation of olefins (AHO) is chosen to demonstrate the utility of our protocol. A meta-model is trained in a binary classification setting to identify highly enantioselective AHO reactions. Two Bayesian meta-learning approaches are considered, namely, deep kernel transfer (DKT) and adaptive deep kernel fitting (ADKF). Both these methods returned better predictions compared to prototypical network. The single-task methods such as random forest and graph neural network performed worse than meta-learning methods. Additionally, we propose another meta-learning approach called ADKF-prior that is shown to further improve the performance in low-data settings. Our meta-learning workflow can be utilized to build a pretrained meta-model for any reaction of interest, which can then be useful to predict the outcome of new but related reactions in a few-shot manner.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"1 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862549","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}
Although a considerable number of chiral nitrogen heterocyclic carbenes (NHCs) have been developed, yet it is highly necessary to develop new NHCs bearing multiple sites for facile modifications of both electronic nature and steric hindrance. Herein, we uncover a new family of chiral non-C2-Symmetric NHCs with a fused sidechain, whose precursors are synthesized by a simple five-step route. The synthesis includes Pd-catalyzed cross-coupling or nucleophilic addition/oxidation, chiral phosphoric acid-catalyzed asymmetric reduction of 2-aryl-quinolines, bromination at C8, Buchwald–Hartwig amination, and cyclization with methyl orthoformate. Among nine prepared NHCs, YC-NHC8 is the optimal ligand for Cu(I)-catalyzed asymmetric SN2′ silylation, YC-NHC3 works as the best ligand for Cu(I)-catalyzed enantioselective conjugate silylation of simple α,β-unsaturated amides, and YC-NHC9 serves as the most suitable ligand for copper(I)-catalyzed asymmetric silylation of azadienes. Remarkably, these three reactions are successfully run under a catalyst loading of 0.1 mol %, indicating that YC-NHCs may have the potential to be broadly used in efficient asymmetric transition metal catalysis.
{"title":"Design, Synthesis, and Application of a Family of Chiral Non-C2-Symmetric NHCs with a Fused Sidechain","authors":"Zhen-Xi Cai, Qi Zhang, Tian-Yu Wei, Hu Tian, Jia-Wei Jiang, Zhang-Yi Wei, Liang Yin","doi":"10.1002/anie.202508572","DOIUrl":"https://doi.org/10.1002/anie.202508572","url":null,"abstract":"Although a considerable number of chiral nitrogen heterocyclic carbenes (NHCs) have been developed, yet it is highly necessary to develop new NHCs bearing multiple sites for facile modifications of both electronic nature and steric hindrance. Herein, we uncover a new family of chiral non-C2-Symmetric NHCs with a fused sidechain, whose precursors are synthesized by a simple five-step route. The synthesis includes Pd-catalyzed cross-coupling or nucleophilic addition/oxidation, chiral phosphoric acid-catalyzed asymmetric reduction of 2-aryl-quinolines, bromination at C8, Buchwald–Hartwig amination, and cyclization with methyl orthoformate. Among nine prepared NHCs, YC-NHC8 is the optimal ligand for Cu(I)-catalyzed asymmetric SN2′ silylation, YC-NHC3 works as the best ligand for Cu(I)-catalyzed enantioselective conjugate silylation of simple α,β-unsaturated amides, and YC-NHC9 serves as the most suitable ligand for copper(I)-catalyzed asymmetric silylation of azadienes. Remarkably, these three reactions are successfully run under a catalyst loading of 0.1 mol %, indicating that YC-NHCs may have the potential to be broadly used in efficient asymmetric transition metal catalysis.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"71 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862567","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}
Traditional design of conductive hydrogels involves embedding conductive components within a hydrated polymeric network to establish interconnected electron pathways. While the hydration shell of the polymeric network is typically considered insulating, we demonstrate that it can, in fact, enhance electron transport. Using a PEDOT:PSS hydrogel, we propose a hierarchical network with an inhomogeneous topological structure, consisting of entangled PSS chains, dense PSS assemblies, and PEDOT microcrystals. In the hydrated state, the dense PSS assemblies significantly lower the energy barrier for electron hopping between PEDOT microcrystals, thereby promoting electron transport. As a result, the charge transport mechanism in these hydrogels is predominantly electronic rather than ionic, effectively mimicking the behavior of electronic conductors. The charge transport rate reaches up to 2 × 106 m/s, which is approximately 5 orders of magnitude higher than that of ion-based processes. This characteristic imparts the hydrogels with kinetically sensitive ion-electron transduction, enabling time-resolved electrochemical analysis of biochemical processes.
{"title":"Boosting Electronic Charge Transport in Conductive Hydrogels via Rapid Ion-Electron Transduction","authors":"Zhou Li, Huiru Yun, Yuke Yan, Yang Zhao, Fei Zhao","doi":"10.1002/anie.202506560","DOIUrl":"https://doi.org/10.1002/anie.202506560","url":null,"abstract":"Traditional design of conductive hydrogels involves embedding conductive components within a hydrated polymeric network to establish interconnected electron pathways. While the hydration shell of the polymeric network is typically considered insulating, we demonstrate that it can, in fact, enhance electron transport. Using a PEDOT:PSS hydrogel, we propose a hierarchical network with an inhomogeneous topological structure, consisting of entangled PSS chains, dense PSS assemblies, and PEDOT microcrystals. In the hydrated state, the dense PSS assemblies significantly lower the energy barrier for electron hopping between PEDOT microcrystals, thereby promoting electron transport. As a result, the charge transport mechanism in these hydrogels is predominantly electronic rather than ionic, effectively mimicking the behavior of electronic conductors. The charge transport rate reaches up to 2 × 106 m/s, which is approximately 5 orders of magnitude higher than that of ion-based processes. This characteristic imparts the hydrogels with kinetically sensitive ion-electron transduction, enabling time-resolved electrochemical analysis of biochemical processes.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"67 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862550","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}
Highly enantioselective hydrogenation of α-hydroxy ketones was achieved by applying the catalytic combination of cobalt acetate and chiral Ph-BPE ligand, supplemented by a carboxylic acid additive promotion strategy. The carboxylic acid additive significantly increases both reactivity and enantioselectivity, allowing for the highly efficient generation of chiral 1,2-diols with up to 99% ee. The application utility is proved through derivations and a total synthesis of (R)-(-)-Eliprodil. Mechanistic studies including control experiments and DFT calculations support the proposed catalytic mechanism and explain the origin of enantioselectivity.
{"title":"Cobalt-Catalyzed Asymmetric Hydrogenation of α-Hydroxy Ketones Enabled by a Carboxylic Acid Additive Promotion Strategy","authors":"Yuxi Song, Yashi Zou, Tiantian Chen, Zhenfeng Zhang, Wanbin Zhang","doi":"10.1002/anie.202504159","DOIUrl":"https://doi.org/10.1002/anie.202504159","url":null,"abstract":"Highly enantioselective hydrogenation of α-hydroxy ketones was achieved by applying the catalytic combination of cobalt acetate and chiral Ph-BPE ligand, supplemented by a carboxylic acid additive promotion strategy. The carboxylic acid additive significantly increases both reactivity and enantioselectivity, allowing for the highly efficient generation of chiral 1,2-diols with up to 99% ee. The application utility is proved through derivations and a total synthesis of (R)-(-)-Eliprodil. Mechanistic studies including control experiments and DFT calculations support the proposed catalytic mechanism and explain the origin of enantioselectivity.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"128 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862568","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}
Menglong Sun, Jiabin Chen, Zhibin Zhang, Yuan Jing, Mengze Zhao, Lili Chen, Kaihui Liu, Chuang Zhang, Xi Wang, Jiannian Yao
The role of surface spin configuration in spin-dependent catalytic reactions remains contentious, particularly when compared to the established dominance of coordination environments. Here, we resolve this debate by systematically probing oxygen reduction reaction (ORR) mechanisms on high-index Ni single-crystal facets ([210], [310], [520]) through integrated density functional theory (DFT) and experimental studies. Contrary to conventional d-band center predictions, we demonstrate that ferromagnetic ordering fundamentally dictates catalytic activity by stabilizing triplet O2 adsorption and lowering spin-forbidden transition barriers. The Ni (210) facet exhibits superior ORR performance (half-wave potential: 0.842 V vs. RHE), outperforming Ni (310) and Ni (520) due to its optimized d-band center alignment and enhanced saturation magnetization. External magnetic fields amplify this effect, yielding a 28% current density enhancement for Ni (210)—nearly triple that of Ni (520). Spin-polarized DFT calculations reveal that ferromagnetic ordering reduces the potential-determining step energy barrier for *OH desorption by 7.0%, overriding coordination-number effects. These findings establish ferromagnetic alignment as a critical design criterion for spin-engineered electrocatalysts, offering a paradigm shift from coordination-centric optimization to spin-polarized interface engineering.
{"title":"Ferromagnetic Ordering Outperforms Coordination Effects in Governing Oxygen Reduction Catalysis on High-index Nickel Single Crystals","authors":"Menglong Sun, Jiabin Chen, Zhibin Zhang, Yuan Jing, Mengze Zhao, Lili Chen, Kaihui Liu, Chuang Zhang, Xi Wang, Jiannian Yao","doi":"10.1002/anie.202504869","DOIUrl":"https://doi.org/10.1002/anie.202504869","url":null,"abstract":"The role of surface spin configuration in spin-dependent catalytic reactions remains contentious, particularly when compared to the established dominance of coordination environments. Here, we resolve this debate by systematically probing oxygen reduction reaction (ORR) mechanisms on high-index Ni single-crystal facets ([210], [310], [520]) through integrated density functional theory (DFT) and experimental studies. Contrary to conventional d-band center predictions, we demonstrate that ferromagnetic ordering fundamentally dictates catalytic activity by stabilizing triplet O2 adsorption and lowering spin-forbidden transition barriers. The Ni (210) facet exhibits superior ORR performance (half-wave potential: 0.842 V vs. RHE), outperforming Ni (310) and Ni (520) due to its optimized d-band center alignment and enhanced saturation magnetization. External magnetic fields amplify this effect, yielding a 28% current density enhancement for Ni (210)—nearly triple that of Ni (520). Spin-polarized DFT calculations reveal that ferromagnetic ordering reduces the potential-determining step energy barrier for *OH desorption by 7.0%, overriding coordination-number effects. These findings establish ferromagnetic alignment as a critical design criterion for spin-engineered electrocatalysts, offering a paradigm shift from coordination-centric optimization to spin-polarized interface engineering.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"3 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862569","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}
Lu Zhang, Xiaoying Kang, Tianjiao Wang, Xuya Yu, Mengyun Liang, Junyan Jiang, Ji Qi, Wen Li
Synergistically improving T cell responsiveness represents a promising therapeutic strategy for tumors; however, current treatments struggle to fully activate cancer-immunity cascade. We propose a novel gas-assisted sonosensitizer-loaded biomimetic nanoplatform, triggering ultrasonic-sensitive tumor immunogenic cell death (ICD) and cascading immune activation. Upon ultrasound stimulation, the nanocore liberates ROS and NO, generating highly toxic peroxynitrite (ONOO-) in situ. The ONOO- then orchestrated several intracellular events, including protein S-nitrosylation, endoplasmic reticulum stress, Ca2+ dyshomeostasis-mediated mitochondrial dysfunction, and ICD-enhanced immune cell recruitment. Furthermore, the biomimetic artificial dendritic cell (DC) membranes, from genetically engineered tumor cells, simultaneously present peptide-major histocompatibility complex class I (pMHC-I) and CD86, enabling homologous tumor targeting but also mimicking the antigen presentation and costimulatory signaling of DCs to directly activate infiltrating T lymphocytes. In multiple murine models, this nanovaccine demonstrated remarkable therapeutic efficacy, including tumor suppression, long-lasting antitumor immunity, and tumor metastasis inhibition. The ultrasound-responsive nanoDCs offer a promising paradigm for multifaceted immune boosters to address the challenges of immune tolerance and suboptimal patient response.
{"title":"NO-Enhanced Sonodynamic Nanovesicles with Co-Stimulatory Molecule Self-Presentation for Multidimensional Tumor Immunotherapy","authors":"Lu Zhang, Xiaoying Kang, Tianjiao Wang, Xuya Yu, Mengyun Liang, Junyan Jiang, Ji Qi, Wen Li","doi":"10.1002/anie.202504684","DOIUrl":"https://doi.org/10.1002/anie.202504684","url":null,"abstract":"Synergistically improving T cell responsiveness represents a promising therapeutic strategy for tumors; however, current treatments struggle to fully activate cancer-immunity cascade. We propose a novel gas-assisted sonosensitizer-loaded biomimetic nanoplatform, triggering ultrasonic-sensitive tumor immunogenic cell death (ICD) and cascading immune activation. Upon ultrasound stimulation, the nanocore liberates ROS and NO, generating highly toxic peroxynitrite (ONOO-) in situ. The ONOO- then orchestrated several intracellular events, including protein S-nitrosylation, endoplasmic reticulum stress, Ca2+ dyshomeostasis-mediated mitochondrial dysfunction, and ICD-enhanced immune cell recruitment. Furthermore, the biomimetic artificial dendritic cell (DC) membranes, from genetically engineered tumor cells, simultaneously present peptide-major histocompatibility complex class I (pMHC-I) and CD86, enabling homologous tumor targeting but also mimicking the antigen presentation and costimulatory signaling of DCs to directly activate infiltrating T lymphocytes. In multiple murine models, this nanovaccine demonstrated remarkable therapeutic efficacy, including tumor suppression, long-lasting antitumor immunity, and tumor metastasis inhibition. The ultrasound-responsive nanoDCs offer a promising paradigm for multifaceted immune boosters to address the challenges of immune tolerance and suboptimal patient response.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"7 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862565","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}
Monica Trincado, Sven Thomas Nappen, Juan José Gamboa-Carballo, Esther Tschanen, Federica Ricatto, Michael Dieter Wörle, Arne Thomas, Hansjörg Grützmacher
Nitrous oxide (N2O) is a valuable oxygen/nitrogen transfer reagent but reactions with N2O are challenging due to its inertness. Consequently, it accumulates in the atmosphere, and because it is both an ozone-depleting reagent and potent green-house gas, effective mitigation methods become important. This study presents rhodium(I) amido bis(olefin) N-heterocyclic carbene complexes [Rh(trop2N)(NHC)] as robust homogeneous catalysts for the direct hydrogenation of N2O. Kinetic experiments and DFT calculations show that increasing π-acidity of the NHC and the presence of water significantly enhance the catalytic efficiency. The rhodium-amido bond facilitates cooperative H2-cleavage and oxygen atom transfer from N2O. The catalyst is regenerated with the loss of water from the hydroxide intermediate [Rh(OH)(trop2NH)(NHC)], which forms a dimeric complex with a central bridging hydrated hydroxide ligand [H3O2]−. Water facilitates dinitrogen (N2) loss from an intermediate containing an oxy-diazene ligand [H–N=N–O]−. The optimized catalyst achieves a TON > 230,000 and TOF > 1,300 h−1.
{"title":"Water Serving as Cocatalyst for the Highly Efficient Homogeneously Catalyzed Conversion of N2O/H2 Mixtures with Optimized Rhodium NHC Complexes","authors":"Monica Trincado, Sven Thomas Nappen, Juan José Gamboa-Carballo, Esther Tschanen, Federica Ricatto, Michael Dieter Wörle, Arne Thomas, Hansjörg Grützmacher","doi":"10.1002/anie.202502616","DOIUrl":"https://doi.org/10.1002/anie.202502616","url":null,"abstract":"Nitrous oxide (N2O) is a valuable oxygen/nitrogen transfer reagent but reactions with N2O are challenging due to its inertness. Consequently, it accumulates in the atmosphere, and because it is both an ozone-depleting reagent and potent green-house gas, effective mitigation methods become important. This study presents rhodium(I) amido bis(olefin) N-heterocyclic carbene complexes [Rh(trop2N)(NHC)] as robust homogeneous catalysts for the direct hydrogenation of N2O. Kinetic experiments and DFT calculations show that increasing π-acidity of the NHC and the presence of water significantly enhance the catalytic efficiency. The rhodium-amido bond facilitates cooperative H2-cleavage and oxygen atom transfer from N2O. The catalyst is regenerated with the loss of water from the hydroxide intermediate [Rh(OH)(trop2NH)(NHC)], which forms a dimeric complex with a central bridging hydrated hydroxide ligand [H3O2]−. Water facilitates dinitrogen (N2) loss from an intermediate containing an oxy-diazene ligand [H–N=N–O]−. The optimized catalyst achieves a TON > 230,000 and TOF > 1,300 h−1.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"262 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862566","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}
Pei Tang, Siqi Guan, Chen Wu, Huize Wu, Ni Lu, Jun Tan, Chunyang Wang, Hui-Ming Cheng, Feng Li
Layered oxide cathode materials with primary-secondary architecture face challenges of inhomogeneous Li+ diffusion and chemomechanical degradation due to misorientations between equiaxed primary particles. While a radial architecture, featuring elongated grains, is widely believed to enhance diffusion, it does not address the root cause of chemomechanical failure—crystallographic misorientation. The impact of crystallography on the electrochemical performance of radially architectured secondary particles, compared to conventional designs, remains poorly understood. Here, by combining transmission Kikuchi diffraction with multimodal characterization, we decipher the crucial role of crystallography in the performance and stability of polycrystalline high-Ni layered oxide cathode materials. Contrary to the conventional belief that a preferential texture induced by the radial architecture is the key to performance enhancement, we uncover that the radial architecturing primarily alters the misorientation distribution by introducing substantially increased low-angle grain boundaries and twin boundaries that significantly mitigate chemomechanical cracking and phase degradation. This crystallographic refinement facilitates enhanced Li+ diffusion between primary particles, ultimately boosting the rate capability and long-term stability of the cathodes. By quantitatively uncovering the crystallographic influence on performance, this work provides a new avenue for optimizing Li+ diffusion kinetics and chemomechanical resilience in polycrystalline cathode materials through crystallographic engineering.
{"title":"Deciphering the Crystallographic Effect in Radially Architectured Polycrystalline Layered Cathode Materials for Lithium-Ion Batteries","authors":"Pei Tang, Siqi Guan, Chen Wu, Huize Wu, Ni Lu, Jun Tan, Chunyang Wang, Hui-Ming Cheng, Feng Li","doi":"10.1002/anie.202503108","DOIUrl":"https://doi.org/10.1002/anie.202503108","url":null,"abstract":"Layered oxide cathode materials with primary-secondary architecture face challenges of inhomogeneous Li+ diffusion and chemomechanical degradation due to misorientations between equiaxed primary particles. While a radial architecture, featuring elongated grains, is widely believed to enhance diffusion, it does not address the root cause of chemomechanical failure—crystallographic misorientation. The impact of crystallography on the electrochemical performance of radially architectured secondary particles, compared to conventional designs, remains poorly understood. Here, by combining transmission Kikuchi diffraction with multimodal characterization, we decipher the crucial role of crystallography in the performance and stability of polycrystalline high-Ni layered oxide cathode materials. Contrary to the conventional belief that a preferential texture induced by the radial architecture is the key to performance enhancement, we uncover that the radial architecturing primarily alters the misorientation distribution by introducing substantially increased low-angle grain boundaries and twin boundaries that significantly mitigate chemomechanical cracking and phase degradation. This crystallographic refinement facilitates enhanced Li+ diffusion between primary particles, ultimately boosting the rate capability and long-term stability of the cathodes. By quantitatively uncovering the crystallographic influence on performance, this work provides a new avenue for optimizing Li+ diffusion kinetics and chemomechanical resilience in polycrystalline cathode materials through crystallographic engineering.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"47 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862548","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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