Pub Date : 2024-12-03DOI: 10.1038/s42004-024-01378-x
Andrew Z. Haddad, Hyungyeon Cha, Liam McDonough, Chaochao Dun, Garrett Pohlman, Jeffrey J. Urban, Robert Kostecki
Electrochemical technologies add a unique dimension for ore refinement, representing tunable methods that can integrate with renewable energy sources and existing downstream process flows. However, the development of electrochemical extraction technologies has been impeded by the technological maturity of hydro- and pyro-metallurgy, as well as the electrical insulating properties of many metal oxide ores. The fabrication and use of carbon/insulating material composite electrodes has been a longstanding method to enable electrochemical activation. Here, using real hectorite ore, we employ this technical approach to fabricate hectorite-carbon black composite electrodes (HCCEs) and achieve electrochemical activation of hectorite. Anodic polarization results in lithium-ion release through a multi-step chemical and electrochemical mechanism that results in 50.7 ± 4.4% removal of lithium from HCCE, alongside other alkaline ions. This technical proof-of-concept study underscores that electrochemical activation of ores can facilitate lattice deterioration and ion removal from ores. Electrochemical technologies for ore refinement provide a unique opportunity to integrate with renewable energy sources but are impeded by the insulating properties of many ores. Here, the authors take inspiration from the lithium-ion battery field and fabricate hectorite–carbon black composite electrodes to enhance electron percolation into hectorite enabling lithium-ion release through a multi-step (electro)chemical mechanism.
{"title":"Electrochemical lithium extraction from hectorite ore","authors":"Andrew Z. Haddad, Hyungyeon Cha, Liam McDonough, Chaochao Dun, Garrett Pohlman, Jeffrey J. Urban, Robert Kostecki","doi":"10.1038/s42004-024-01378-x","DOIUrl":"10.1038/s42004-024-01378-x","url":null,"abstract":"Electrochemical technologies add a unique dimension for ore refinement, representing tunable methods that can integrate with renewable energy sources and existing downstream process flows. However, the development of electrochemical extraction technologies has been impeded by the technological maturity of hydro- and pyro-metallurgy, as well as the electrical insulating properties of many metal oxide ores. The fabrication and use of carbon/insulating material composite electrodes has been a longstanding method to enable electrochemical activation. Here, using real hectorite ore, we employ this technical approach to fabricate hectorite-carbon black composite electrodes (HCCEs) and achieve electrochemical activation of hectorite. Anodic polarization results in lithium-ion release through a multi-step chemical and electrochemical mechanism that results in 50.7 ± 4.4% removal of lithium from HCCE, alongside other alkaline ions. This technical proof-of-concept study underscores that electrochemical activation of ores can facilitate lattice deterioration and ion removal from ores. Electrochemical technologies for ore refinement provide a unique opportunity to integrate with renewable energy sources but are impeded by the insulating properties of many ores. Here, the authors take inspiration from the lithium-ion battery field and fabricate hectorite–carbon black composite electrodes to enhance electron percolation into hectorite enabling lithium-ion release through a multi-step (electro)chemical mechanism.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-8"},"PeriodicalIF":5.9,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42004-024-01378-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1038/s42004-024-01383-0
Sota Yamada, Eita Sasaki, Hisashi Ohno, Kenjiro Hanaoka
Targeted drug delivery in response to external stimuli is therapeutically desirable, but long-term drug retention at the target site after stimulation is turned off remains a challenge. Herein, we present a targeted-delivery strategy via irreversible aggregation of drug carriers in response to mild external heating. We constructed two types of polymeric micelles, DBCO-TRM and Az-TRM, having a thermo-responsive polymer shell based on N-isopropylacrylamide (NIPAAm) and incorporating alkyne and azide moieties, respectively. Upon heating at 42 °C, the micelles aggregated through hydrophobic interaction between their dehydrated shells. Further, the azide moieties of Az-TRM become exposed on the surface due to the thermally shrinkage of the shells, thereby enabling crosslinking between the two types of micelles via azide-alkyne click chemistry to form irreversible aggregates. These aggregates were efficiently accumulated at tumor sites in mice by local heating after intravenous administration of a mixture of the micelles, and were well retained after cessation of heating due to their increased size. As proof of concept, we show that delivery of doxorubicin in this heat-guided drug delivery system dramatically improved the anti-tumor effect in a mouse model after a single treatment. Our results suggest that this platform could be an efficient tool for on-demand drug delivery. Targeted drug delivery in response to external stimuli is therapeutically desirable, but long-term drug retention at the target site after stimulation is turned off remains a challenge. Here, the authors present a targeted delivery strategy via irreversible aggregation of drug carriers in response to mild external heating by constructing two types of polymeric micelles with a thermo-responsive polymer shell based on N-isopropylacrylamide and incorporating alkyne and azide moieties, respectively.
{"title":"Heat-guided drug delivery via thermally induced crosslinking of polymeric micelles","authors":"Sota Yamada, Eita Sasaki, Hisashi Ohno, Kenjiro Hanaoka","doi":"10.1038/s42004-024-01383-0","DOIUrl":"10.1038/s42004-024-01383-0","url":null,"abstract":"Targeted drug delivery in response to external stimuli is therapeutically desirable, but long-term drug retention at the target site after stimulation is turned off remains a challenge. Herein, we present a targeted-delivery strategy via irreversible aggregation of drug carriers in response to mild external heating. We constructed two types of polymeric micelles, DBCO-TRM and Az-TRM, having a thermo-responsive polymer shell based on N-isopropylacrylamide (NIPAAm) and incorporating alkyne and azide moieties, respectively. Upon heating at 42 °C, the micelles aggregated through hydrophobic interaction between their dehydrated shells. Further, the azide moieties of Az-TRM become exposed on the surface due to the thermally shrinkage of the shells, thereby enabling crosslinking between the two types of micelles via azide-alkyne click chemistry to form irreversible aggregates. These aggregates were efficiently accumulated at tumor sites in mice by local heating after intravenous administration of a mixture of the micelles, and were well retained after cessation of heating due to their increased size. As proof of concept, we show that delivery of doxorubicin in this heat-guided drug delivery system dramatically improved the anti-tumor effect in a mouse model after a single treatment. Our results suggest that this platform could be an efficient tool for on-demand drug delivery. Targeted drug delivery in response to external stimuli is therapeutically desirable, but long-term drug retention at the target site after stimulation is turned off remains a challenge. Here, the authors present a targeted delivery strategy via irreversible aggregation of drug carriers in response to mild external heating by constructing two types of polymeric micelles with a thermo-responsive polymer shell based on N-isopropylacrylamide and incorporating alkyne and azide moieties, respectively.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-9"},"PeriodicalIF":5.9,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42004-024-01383-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1038/s42004-024-01376-z
Charbel D. Assaf, Xin Gui, Oleg G. Salnikov, Arne Brahms, Nikita V. Chukanov, Ivan V. Skovpin, Eduard Y. Chekmenev, Rainer Herges, Simon B. Duckett, Igor V. Koptyug, Kai Buckenmaier, Rainer Körber, Markus Plaumann, Alexander A. Auer, Jan-Bernd Hövener, Andrey N. Pravdivtsev
The signal amplification by reversible exchange process (SABRE) enhances NMR signals by unlocking hidden polarization in parahydrogen through interactions with to-be-hyperpolarized substrate molecules when both are transiently bound to an Ir-based organometallic catalyst. Recent efforts focus on optimizing polarization transfer from parahydrogen-derived hydride ligands to the substrate in SABRE. However, this requires quantitative information on ligand exchange rates, which common NMR techniques struggle to provide. Here, we introduce an experimental spin order transfer sequence, with readout occurring at 15N nuclei directly interacting with the catalyst. Enhanced 15N NMR signals overcome sensitivity challenges, encoding substrate dissociation rates. This methodology enables robust data fitting to ligand exchange models, yielding substrate dissociation rate constants with higher precision than classical 1D and 2D 1H NMR approaches. This refinement improves the accuracy of key activation enthalpy ΔH‡ and entropy ΔS‡ estimates. Furthermore, the higher chemical shift dispersion provided by enhanced 15N NMR reveals the kinetics of substrate dissociation for acetonitrile and metronidazole, previously inaccessible via 1H NMR due to small chemical shift differences between free and Ir-bound substrates. The presented approach can be successfully applied not only to isotopically enriched substrates but also to compounds with natural abundance of the to-be-hyperpolarized heteronuclei. Current efforts to enhance NMR signals using the signal amplification by reversible exchange (SABRE) focus on optimizing polarization transfer from parahydrogen-derived hydride ligands to the substrate, but this requires quantitative information on ligand exchange rates, which common NMR techniques struggle to provide. Here, the authors introduce an experimental spin order transfer sequence with readout occurring at hyperpolarization-enhanced 15N nuclei that are directly interacting with the SABRE catalyst, enabling robust evaluation of ligand chemical exchange.
{"title":"Analysis of chemical exchange in iridium N-heterocyclic carbene complexes using heteronuclear parahydrogen-enhanced NMR","authors":"Charbel D. Assaf, Xin Gui, Oleg G. Salnikov, Arne Brahms, Nikita V. Chukanov, Ivan V. Skovpin, Eduard Y. Chekmenev, Rainer Herges, Simon B. Duckett, Igor V. Koptyug, Kai Buckenmaier, Rainer Körber, Markus Plaumann, Alexander A. Auer, Jan-Bernd Hövener, Andrey N. Pravdivtsev","doi":"10.1038/s42004-024-01376-z","DOIUrl":"10.1038/s42004-024-01376-z","url":null,"abstract":"The signal amplification by reversible exchange process (SABRE) enhances NMR signals by unlocking hidden polarization in parahydrogen through interactions with to-be-hyperpolarized substrate molecules when both are transiently bound to an Ir-based organometallic catalyst. Recent efforts focus on optimizing polarization transfer from parahydrogen-derived hydride ligands to the substrate in SABRE. However, this requires quantitative information on ligand exchange rates, which common NMR techniques struggle to provide. Here, we introduce an experimental spin order transfer sequence, with readout occurring at 15N nuclei directly interacting with the catalyst. Enhanced 15N NMR signals overcome sensitivity challenges, encoding substrate dissociation rates. This methodology enables robust data fitting to ligand exchange models, yielding substrate dissociation rate constants with higher precision than classical 1D and 2D 1H NMR approaches. This refinement improves the accuracy of key activation enthalpy ΔH‡ and entropy ΔS‡ estimates. Furthermore, the higher chemical shift dispersion provided by enhanced 15N NMR reveals the kinetics of substrate dissociation for acetonitrile and metronidazole, previously inaccessible via 1H NMR due to small chemical shift differences between free and Ir-bound substrates. The presented approach can be successfully applied not only to isotopically enriched substrates but also to compounds with natural abundance of the to-be-hyperpolarized heteronuclei. Current efforts to enhance NMR signals using the signal amplification by reversible exchange (SABRE) focus on optimizing polarization transfer from parahydrogen-derived hydride ligands to the substrate, but this requires quantitative information on ligand exchange rates, which common NMR techniques struggle to provide. Here, the authors introduce an experimental spin order transfer sequence with readout occurring at hyperpolarization-enhanced 15N nuclei that are directly interacting with the SABRE catalyst, enabling robust evaluation of ligand chemical exchange.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-10"},"PeriodicalIF":5.9,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42004-024-01376-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1038/s42004-024-01380-3
Aurora J. Cruz-Cabeza, Peter R. Spackman, Amy V. Hall
Supramolecular synthon and hydrogen bond pairing approaches have influenced the understanding of cocrystal formation for decades, but are hydrogen bonds really the dominant interaction in cocrystals? To investigate this, an extensive analysis of 1:1 two-component cocrystals in the Cambridge Structural Database was undertaken, revealing that stacking and T-type interactions are just as, if not more important than hydrogen bonds in molecular cocrystals. A total of 84% of the most common coformers in the dataset are aromatic. When analysing cocrystal dimers, only 20% consist of solely strong hydrogen bonds, with over 50% of contacts involving stacking and T-type interactions. Combining interaction strength and frequency, both hydrogen bond and stacking/T-type interactions contribute equally to the stabilisation of cocrystal lattices. Therefore, we state that crystal engineering and cocrystal design concepts of the future should not solely revolve around supramolecular synthon pairing via hydrogen bonds, but instead consider optimising both hydrogen bonding and stacking/T-type interactions. Hydrogen bond pairing and supramolecular synthon approaches have influenced the understanding of cocrystal formation for decades, but whether or not hydrogen bonds are the dominant interaction in cocrystals has not been extensively studied. Here, the authors perform an extensive analysis of 1:1 two-component cocrystals in the Cambridge Structural Database and reveal that when interaction strength and frequency are combined, hydrogen bonds and stacking/T-type interactions contribute equally to the stabilisation of cocrystal lattices.
{"title":"The interplay between hydrogen bonds and stacking/T-type interactions in molecular cocrystals","authors":"Aurora J. Cruz-Cabeza, Peter R. Spackman, Amy V. Hall","doi":"10.1038/s42004-024-01380-3","DOIUrl":"10.1038/s42004-024-01380-3","url":null,"abstract":"Supramolecular synthon and hydrogen bond pairing approaches have influenced the understanding of cocrystal formation for decades, but are hydrogen bonds really the dominant interaction in cocrystals? To investigate this, an extensive analysis of 1:1 two-component cocrystals in the Cambridge Structural Database was undertaken, revealing that stacking and T-type interactions are just as, if not more important than hydrogen bonds in molecular cocrystals. A total of 84% of the most common coformers in the dataset are aromatic. When analysing cocrystal dimers, only 20% consist of solely strong hydrogen bonds, with over 50% of contacts involving stacking and T-type interactions. Combining interaction strength and frequency, both hydrogen bond and stacking/T-type interactions contribute equally to the stabilisation of cocrystal lattices. Therefore, we state that crystal engineering and cocrystal design concepts of the future should not solely revolve around supramolecular synthon pairing via hydrogen bonds, but instead consider optimising both hydrogen bonding and stacking/T-type interactions. Hydrogen bond pairing and supramolecular synthon approaches have influenced the understanding of cocrystal formation for decades, but whether or not hydrogen bonds are the dominant interaction in cocrystals has not been extensively studied. Here, the authors perform an extensive analysis of 1:1 two-component cocrystals in the Cambridge Structural Database and reveal that when interaction strength and frequency are combined, hydrogen bonds and stacking/T-type interactions contribute equally to the stabilisation of cocrystal lattices.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-9"},"PeriodicalIF":5.9,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42004-024-01380-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon quantum dots (CQDs) have recently received a lot of attention due to their unique physical properties, and their environmentally friendly features such as low toxicity and high biocompatibility. Supercritical fluids, which possess unusual properties such as high solubility, high diffusivity, low viscosity and zero surface tension, are now commonly used particularly in the fields of electronic, chemical and materials science and engineering. Here, we synthesise carbon nano/microparticles in supercritical acetone, in which neither external molecules nor starting materials are dissolved/dispersed. We find that carbon microparticles and nano structures such as graphene quantum dots (GQDs), carbon nano onions (CNOs) and elongated carbon nano onions (eCNOs) are self-assembled via thermal decomposition of acetone under its supercritical conditions. We also find that the carbon microparticles are in fact formed by GQDs, CNOs and eCNOs, the microparticles being physically resolved into GQDs, CNOs and eCNOs with sonication. The fluorescence features of the carbon nano structures are clarified, noting that no photobleaching was observed for at least one month. The present result may well lead to the development of facile bottom-up methodologies for synthesising nano materials in solvents under their supercritical conditions without using any external precursors/starting materials. Carbon quantum dots are of interest for a range of applications thanks to their unique physical and eco-friendly properties, and facile bottom-up methods to synthesize these are thus in demand. Here, the authors report the bottom-up synthesis of carbon quantum dots and microparticles via the thermal decomposition of supercritical acetone, in the absence of any external precursors/starting materials
{"title":"Precursor-free synthesis of carbon quantum dots and carbon microparticles in supercritical acetone","authors":"Shunji Kurosu, Yuma Kaizuka, Kang Zhou, Haruki Yokota, Ryusuké Hashimoto, Keiichi Yanagisawa, Hirokazu Shimoshigé, Yuri Tanuma, Hisao Morimoto, Toru Maekawa","doi":"10.1038/s42004-024-01367-0","DOIUrl":"10.1038/s42004-024-01367-0","url":null,"abstract":"Carbon quantum dots (CQDs) have recently received a lot of attention due to their unique physical properties, and their environmentally friendly features such as low toxicity and high biocompatibility. Supercritical fluids, which possess unusual properties such as high solubility, high diffusivity, low viscosity and zero surface tension, are now commonly used particularly in the fields of electronic, chemical and materials science and engineering. Here, we synthesise carbon nano/microparticles in supercritical acetone, in which neither external molecules nor starting materials are dissolved/dispersed. We find that carbon microparticles and nano structures such as graphene quantum dots (GQDs), carbon nano onions (CNOs) and elongated carbon nano onions (eCNOs) are self-assembled via thermal decomposition of acetone under its supercritical conditions. We also find that the carbon microparticles are in fact formed by GQDs, CNOs and eCNOs, the microparticles being physically resolved into GQDs, CNOs and eCNOs with sonication. The fluorescence features of the carbon nano structures are clarified, noting that no photobleaching was observed for at least one month. The present result may well lead to the development of facile bottom-up methodologies for synthesising nano materials in solvents under their supercritical conditions without using any external precursors/starting materials. Carbon quantum dots are of interest for a range of applications thanks to their unique physical and eco-friendly properties, and facile bottom-up methods to synthesize these are thus in demand. Here, the authors report the bottom-up synthesis of carbon quantum dots and microparticles via the thermal decomposition of supercritical acetone, in the absence of any external precursors/starting materials","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-8"},"PeriodicalIF":5.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11608273/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1038/s42004-024-01369-y
Efthymios Oikonomou, Yannick Juli, Rajkumar Reddy Kolan, Linda Kern, Thomas Gruber, Christian Alzheimer, Patrick Krauss, Andreas Maier, Tobias Huth
The patch-clamp technique allows us to eavesdrop the gating behavior of individual ion channels with unprecedented temporal resolution. The signals arise from conformational changes of the channel protein as it makes rapid transitions between conducting and non-conducting states. However, unambiguous analysis of single-channel datasets is challenging given the inadvertently low signal-to-noise ratio as well as signal distortions caused by low-pass filtering. Ion channel kinetics are typically described using hidden Markov models (HMM), which allow conclusions on the inner workings of the protein. In this study, we present a Deep Learning approach for extracting models from single-channel recordings. Two-dimensional dwell-time histograms are computed from the idealized time series and are subsequently analyzed by two neural networks, that have been trained on simulated datasets, to determine the topology and the transition rates of the HMM. We show that this method is robust regarding noise and gating events beyond the corner frequency of the low-pass filter. In addition, we propose a method to evaluate the goodness of a predicted model by re-simulating the prediction. Finally, we tested the algorithm with data recorded on a patch-clamp setup. In principle, it meets the requirements for model extraction during an ongoing recording session in real-time. The patch-clamp technique enables probing of the gating behavior of individual ion channel proteins, but unambiguous analysis of single-channel datasets is challenging. Here, the authors present a deep learning approach for extracting Markov models from single-channel recordings.
{"title":"A deep learning approach to real-time Markov modeling of ion channel gating","authors":"Efthymios Oikonomou, Yannick Juli, Rajkumar Reddy Kolan, Linda Kern, Thomas Gruber, Christian Alzheimer, Patrick Krauss, Andreas Maier, Tobias Huth","doi":"10.1038/s42004-024-01369-y","DOIUrl":"10.1038/s42004-024-01369-y","url":null,"abstract":"The patch-clamp technique allows us to eavesdrop the gating behavior of individual ion channels with unprecedented temporal resolution. The signals arise from conformational changes of the channel protein as it makes rapid transitions between conducting and non-conducting states. However, unambiguous analysis of single-channel datasets is challenging given the inadvertently low signal-to-noise ratio as well as signal distortions caused by low-pass filtering. Ion channel kinetics are typically described using hidden Markov models (HMM), which allow conclusions on the inner workings of the protein. In this study, we present a Deep Learning approach for extracting models from single-channel recordings. Two-dimensional dwell-time histograms are computed from the idealized time series and are subsequently analyzed by two neural networks, that have been trained on simulated datasets, to determine the topology and the transition rates of the HMM. We show that this method is robust regarding noise and gating events beyond the corner frequency of the low-pass filter. In addition, we propose a method to evaluate the goodness of a predicted model by re-simulating the prediction. Finally, we tested the algorithm with data recorded on a patch-clamp setup. In principle, it meets the requirements for model extraction during an ongoing recording session in real-time. The patch-clamp technique enables probing of the gating behavior of individual ion channel proteins, but unambiguous analysis of single-channel datasets is challenging. Here, the authors present a deep learning approach for extracting Markov models from single-channel recordings.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-16"},"PeriodicalIF":5.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11608338/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1038/s42004-024-01366-1
Kentaro Maejima, Heishun Zen, Hiroyasu Sato, Eiji Nishibori, Tomoya Enjou, Youhei Takeda, Satoshi Minakata, Eri Hisamura, Ken Albrecht, Yuka Ikemoto, Irene Badía-Domínguez, Juan Sánchez-Rincón, M. Carmen Ruiz Delgado, Yohei Yamamoto, Hiroshi Yamagishi
Flexibility has been pursued enthusiastically in the field of porous crystals for enhancing their adsorption and separation performances. However, flexibility has never been observed among porous crystals sustained thoroughly by van der Waals interactions since flexible motions readily lead to the collapse of the porous architecture. Here we report a van der Waals crystal featuring conformational flexibility as well as permanent microporosity. The single-crystal structure and its structural transition in response to the adsorption of water molecules were unambiguously disclosed by means of electron and X-ray crystal structure analyses. The peripheral aromatic rings of the constituent molecule rotated as increasing the ambient humidity, while the connectivity of the pores was maintained throughout the structural transition. The transformative pores allowed the guest water molecules to move exceedingly quickly through the pores with a time constant of 490 μs. We demonstrated that the quick release of water induced by photothermal heating induced a significant upward bending of a film set above the crystalline powder compared to conventional porous materials. This finding contributes to the future crystal engineering based on van der Waals interactions rather than cohesive bonds. Flexibility in porous crystals can enhance their adsorption and separation performances, however, achieving flexibility in porous crystals sustained solely through van der Waals interactions is challenging given that flexible motions typically lead to framework collapse. Here, the authors present a van der Waals crystal that features both conformational flexibility and permanent microporosity
{"title":"A van der Waals porous crystal featuring conformational flexibility and permanent porosity for ultrafast water release","authors":"Kentaro Maejima, Heishun Zen, Hiroyasu Sato, Eiji Nishibori, Tomoya Enjou, Youhei Takeda, Satoshi Minakata, Eri Hisamura, Ken Albrecht, Yuka Ikemoto, Irene Badía-Domínguez, Juan Sánchez-Rincón, M. Carmen Ruiz Delgado, Yohei Yamamoto, Hiroshi Yamagishi","doi":"10.1038/s42004-024-01366-1","DOIUrl":"10.1038/s42004-024-01366-1","url":null,"abstract":"Flexibility has been pursued enthusiastically in the field of porous crystals for enhancing their adsorption and separation performances. However, flexibility has never been observed among porous crystals sustained thoroughly by van der Waals interactions since flexible motions readily lead to the collapse of the porous architecture. Here we report a van der Waals crystal featuring conformational flexibility as well as permanent microporosity. The single-crystal structure and its structural transition in response to the adsorption of water molecules were unambiguously disclosed by means of electron and X-ray crystal structure analyses. The peripheral aromatic rings of the constituent molecule rotated as increasing the ambient humidity, while the connectivity of the pores was maintained throughout the structural transition. The transformative pores allowed the guest water molecules to move exceedingly quickly through the pores with a time constant of 490 μs. We demonstrated that the quick release of water induced by photothermal heating induced a significant upward bending of a film set above the crystalline powder compared to conventional porous materials. This finding contributes to the future crystal engineering based on van der Waals interactions rather than cohesive bonds. Flexibility in porous crystals can enhance their adsorption and separation performances, however, achieving flexibility in porous crystals sustained solely through van der Waals interactions is challenging given that flexible motions typically lead to framework collapse. Here, the authors present a van der Waals crystal that features both conformational flexibility and permanent microporosity","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-9"},"PeriodicalIF":5.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11608220/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pyridazine derivatives hold significant interest due to their broad applications in pharmaceuticals and materials science, where they serve as valuable scaffolds for bioactive compounds and functional materials. Here, we report a formal [4 + 2] reaction for the synthesis of 5’-sulfonyl-4’-aryl-3-cyano substituted pyridazine compounds from the reaction between vinylogous enaminonitriles and sulfonyl hydrazides. The key features of our pyridazine synthesis include the transamidation of vinylogous enaminonitriles with sulfonyl hydrazide, radical sulfonylation of the resulting intermediate, and subsequent 6-endo-trig radical cyclization. This reaction proceeds smoothly to deliver a series of pyridazine derivatives in good to high yields. We also found that the sulfonyl group of the synthesized pyridazines can be transformed into C-, O-, or N-containing functional groups. A gram-scale experiment and a diverse transformation of synthesized pyridazines were also performed to validate the practicality of our developed process. In the synthesis of sulfonyl-substituted pyridazines, a 6-endo-trig cyclization via a radical pathway is both kinetically and thermodynamically favored over the cyclization via an ionic pathway, as supported by DFT calculations. Pyridazine is an aromatic heterocyclic compound that is utilized as a bioisostere for benzene or pyridine, and is found in the core scaffold of various drug molecules, making synthetic methods to access pyridazine scaffolds of high interest. Here, the authors report the synthesis of 5’-sulfonyl-4’-aryl-3-cyano substituted pyridazine compounds from a formal [4 + 2] reaction between vinylogous enaminonitriles and sulfonyl hydrazides.
{"title":"Formal [4 + 2] combined ionic and radical approach of vinylogous enaminonitriles to access highly substituted sulfonyl pyridazines","authors":"Chanhyun Jung, Kwanghee Lee, Shanmugam Rajasekar, Ji-Youn Yim, Jaeuk Sim, Young Hee Lee, Jae-Hwan Kwak, Soonsil Hyun, Young Kee Kang, Mayavan Viji, Jae-Kyung Jung","doi":"10.1038/s42004-024-01368-z","DOIUrl":"10.1038/s42004-024-01368-z","url":null,"abstract":"Pyridazine derivatives hold significant interest due to their broad applications in pharmaceuticals and materials science, where they serve as valuable scaffolds for bioactive compounds and functional materials. Here, we report a formal [4 + 2] reaction for the synthesis of 5’-sulfonyl-4’-aryl-3-cyano substituted pyridazine compounds from the reaction between vinylogous enaminonitriles and sulfonyl hydrazides. The key features of our pyridazine synthesis include the transamidation of vinylogous enaminonitriles with sulfonyl hydrazide, radical sulfonylation of the resulting intermediate, and subsequent 6-endo-trig radical cyclization. This reaction proceeds smoothly to deliver a series of pyridazine derivatives in good to high yields. We also found that the sulfonyl group of the synthesized pyridazines can be transformed into C-, O-, or N-containing functional groups. A gram-scale experiment and a diverse transformation of synthesized pyridazines were also performed to validate the practicality of our developed process. In the synthesis of sulfonyl-substituted pyridazines, a 6-endo-trig cyclization via a radical pathway is both kinetically and thermodynamically favored over the cyclization via an ionic pathway, as supported by DFT calculations. Pyridazine is an aromatic heterocyclic compound that is utilized as a bioisostere for benzene or pyridine, and is found in the core scaffold of various drug molecules, making synthetic methods to access pyridazine scaffolds of high interest. Here, the authors report the synthesis of 5’-sulfonyl-4’-aryl-3-cyano substituted pyridazine compounds from a formal [4 + 2] reaction between vinylogous enaminonitriles and sulfonyl hydrazides.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-11"},"PeriodicalIF":5.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11608332/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142766944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1038/s42004-024-01371-4
Dongrun Ju, Vrinda Modi, Rahul L. Khade, Yong Zhang
Engineered heme proteins exhibit excellent sustainable catalytic carbene transfer reactivities toward olefins for value-added cyclopropanes. However, unactivated and electron-deficient olefins remain challenging in such reactions. To help design efficient heme-inspired biocatalysts for these difficult situations, a systematic quantum chemical mechanistic study was performed to investigate effects of olefin substituents, non-native amino acid axial ligands, and natural and non-natural macrocycles with the widely used ethyl diazoacetate. Results show that electron-deficient substrate ethyl acrylate has a much higher barrier than the electron-rich styrene. For styrene, the predicted barrier trend is consistent with experimentally used heme analogue cofactors, which can significantly reduce barriers. For ethyl acrylate, while the best non-native axial ligand only marginally improves the reactivity versus the native histidine model, a couple of computationally studied macrocycles can dramatically reduce barriers to the level comparable to styrene. These results will facilitate the development of better biocatalysts in this area. Engineered heme proteins exhibit excellent sustainable catalytic carbene transfer reactivities enabling the transformation of olefins to cyclopropanes, however, exploiting unactivated and electron-deficient olefins in such reactions remains challenging. Here, the authors perform a quantum chemical mechanistic study to investigate the effects of olefin substituents, non-native amino acid axial ligands, and natural and non-natural macrocycles with the widely used ethyl diazoacetate, revealing the potential to design an efficient heme-inspired biocatalyst.
{"title":"Mechanistic investigation of sustainable heme-inspired biocatalytic synthesis of cyclopropanes for challenging substrates","authors":"Dongrun Ju, Vrinda Modi, Rahul L. Khade, Yong Zhang","doi":"10.1038/s42004-024-01371-4","DOIUrl":"10.1038/s42004-024-01371-4","url":null,"abstract":"Engineered heme proteins exhibit excellent sustainable catalytic carbene transfer reactivities toward olefins for value-added cyclopropanes. However, unactivated and electron-deficient olefins remain challenging in such reactions. To help design efficient heme-inspired biocatalysts for these difficult situations, a systematic quantum chemical mechanistic study was performed to investigate effects of olefin substituents, non-native amino acid axial ligands, and natural and non-natural macrocycles with the widely used ethyl diazoacetate. Results show that electron-deficient substrate ethyl acrylate has a much higher barrier than the electron-rich styrene. For styrene, the predicted barrier trend is consistent with experimentally used heme analogue cofactors, which can significantly reduce barriers. For ethyl acrylate, while the best non-native axial ligand only marginally improves the reactivity versus the native histidine model, a couple of computationally studied macrocycles can dramatically reduce barriers to the level comparable to styrene. These results will facilitate the development of better biocatalysts in this area. Engineered heme proteins exhibit excellent sustainable catalytic carbene transfer reactivities enabling the transformation of olefins to cyclopropanes, however, exploiting unactivated and electron-deficient olefins in such reactions remains challenging. Here, the authors perform a quantum chemical mechanistic study to investigate the effects of olefin substituents, non-native amino acid axial ligands, and natural and non-natural macrocycles with the widely used ethyl diazoacetate, revealing the potential to design an efficient heme-inspired biocatalyst.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-11"},"PeriodicalIF":5.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11606945/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1038/s42004-024-01375-0
Ilario Baù, Cecilia Poderi, Francesca Sardu, Alessia Giancola, Anna Turchetti, Paola Franchi, Lorenzo Casimiro, Leonardo Andreoni, Serena Silvi, Elisabetta Mezzina, Marco Lucarini
Nitroxide radicals are widely utilized as catalysts for the oxidation of primary alcohols. Here, the aerobic catalytic oxidation cycle of nitroxide radicals has been implemented within a mechanically interlocked rotaxane architecture consisting of a paramagnetic crown ether, which is confined by a molecular axle containing a dialkylammonium station and a 1,2,3-triazole unit. The rotaxane is engineered to exploit the oxidation of a primary alcohol: the primary catalyst is the wheel, a nitroxide radical capable of altering its oxidation state during the catalytic cycle, while the co-oxidant is the Cerium(IV)/O2 couple. The synthesis of the proposed rotaxane, along with its characterization using EPR, HRMS, voltammetry and NMR data, is reported in the paper. The aerobic catalytic oxidation cycle was further investigated using EPR, NMR and GC-MS analyses. This study can aid in the design of autonomously driven molecular machines that exploit the aerobic catalytic oxidation of nitroxide radicals. Catalytic cycles have been demonstrated in mechanically interlocked systems. Here, the authors report a [2]rotaxane containing a nitroxidic radical macrocycle and establish the efficiency of its catalytic redox cycle in this constrained environment.
{"title":"Rotaxane-catalyzed aerobic oxidation of primary alcohols","authors":"Ilario Baù, Cecilia Poderi, Francesca Sardu, Alessia Giancola, Anna Turchetti, Paola Franchi, Lorenzo Casimiro, Leonardo Andreoni, Serena Silvi, Elisabetta Mezzina, Marco Lucarini","doi":"10.1038/s42004-024-01375-0","DOIUrl":"10.1038/s42004-024-01375-0","url":null,"abstract":"Nitroxide radicals are widely utilized as catalysts for the oxidation of primary alcohols. Here, the aerobic catalytic oxidation cycle of nitroxide radicals has been implemented within a mechanically interlocked rotaxane architecture consisting of a paramagnetic crown ether, which is confined by a molecular axle containing a dialkylammonium station and a 1,2,3-triazole unit. The rotaxane is engineered to exploit the oxidation of a primary alcohol: the primary catalyst is the wheel, a nitroxide radical capable of altering its oxidation state during the catalytic cycle, while the co-oxidant is the Cerium(IV)/O2 couple. The synthesis of the proposed rotaxane, along with its characterization using EPR, HRMS, voltammetry and NMR data, is reported in the paper. The aerobic catalytic oxidation cycle was further investigated using EPR, NMR and GC-MS analyses. This study can aid in the design of autonomously driven molecular machines that exploit the aerobic catalytic oxidation of nitroxide radicals. Catalytic cycles have been demonstrated in mechanically interlocked systems. Here, the authors report a [2]rotaxane containing a nitroxidic radical macrocycle and establish the efficiency of its catalytic redox cycle in this constrained environment.","PeriodicalId":10529,"journal":{"name":"Communications Chemistry","volume":" ","pages":"1-7"},"PeriodicalIF":5.9,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11603149/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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