{"title":"Microdroplet Chemistry with Unactivated Droplets","authors":"Huan Chen, Xiaoxu Li, Bowen Li, Yeye Chen, Haoran Ouyang, Youcun Li, Xinxing Zhang","doi":"10.1021/jacs.5c01072","DOIUrl":"https://doi.org/10.1021/jacs.5c01072","url":null,"abstract":"Microdroplet chemistry has attracted much attention owing to its ability to accelerate otherwise slow reactions and to trigger thermodynamically forbidden reactions. The cause of this unique behavior is the intrinsic properties of the droplets, such as the spontaneously generated electric field on the droplet surface. However, some have argued that the droplet generation methods provided energy to the reactions, and the different interfaces that the droplets contact also played important roles; therefore, it is the droplet activation or the environment, not the intrinsic properties, that is responsible for the observed chemistry. In this study, we used adiabatic expansion and dry ice in water to generate homogeneous, contactless, supercooled, and unactivated microdroplets. A large variety of reactions were successfully tested. We opine that it is the intrinsic properties, and not droplet activation, that are responsible for microdroplet chemistry.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"93 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672747","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}
Esun Selvam, Zoé O. G. Schyns, Jessie A. Sun, Pavel A. Kots, Yeonsu Kwak, LaShanda T. J. Korley, Raul F. Lobo, Dionisios G. Vlachos
{"title":"Conversion of Compositionally Diverse Plastic Waste over Earth-Abundant Sulfides","authors":"Esun Selvam, Zoé O. G. Schyns, Jessie A. Sun, Pavel A. Kots, Yeonsu Kwak, LaShanda T. J. Korley, Raul F. Lobo, Dionisios G. Vlachos","doi":"10.1021/jacs.4c18001","DOIUrl":"https://doi.org/10.1021/jacs.4c18001","url":null,"abstract":"Chemical deconstruction of polyolefin plastic wastes via hydroconversion is promising for mitigating plastic accumulation in landfills and the environment. However, hydroconversion catalysts cannot handle complex feedstocks containing multiple polymers, additives, and heteroatom impurities. Here, we report a single-step strategy using earth-abundant metal sulfide catalysts to deconstruct these wastes. We show that NiMoS<sub><i>x</i></sub>/HY catalysts deconstruct polyolefin feedstocks, achieving ∼81–94% selectivity to liquid products. Postsynthetic zeolite modification enhances the catalyst’s activity by >2.5 times, achieving over 95% selectivity to liquid fuels with controllable product distribution in the naphtha, jet fuel, and diesel range. The catalyst is resilient to increasingly complex feedstocks, such as additive-containing polymers and mixed plastics composed of polyolefins and heteroatom-containing polymers, including poly(vinyl chloride). We extend the strategy to single-use polyolefin wastes that can generate toxic byproducts, such as HCl and NH<sub>3</sub>, and eliminate their emissions by integrating reaction and sorption in a one-step process.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"183 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reversible Optical Control of Receptor Tyrosine Kinase Activity and ERK Dynamics Using Azobenzene-Carrying DNA Aptamer Agonist","authors":"Masahiro Wakano, Masaya Tsunoda, Keiji Murayama, Jumpei Morimoto, Ryosuke Ueki, Saeko Aoyama-Ishiwatari, Yusuke Hirabayashi, Hiroyuki Asanuma, Shinsuke Sando","doi":"10.1021/jacs.5c01559","DOIUrl":"https://doi.org/10.1021/jacs.5c01559","url":null,"abstract":"Receptor tyrosine kinases (RTKs) play a pivotal role in cell signaling through their activation via dimerization. Recent studies have demonstrated the importance of the temporal dynamics of RTK activity and downstream signals, such as ERK, in determining the cell fate. To better understand these dynamics, it is essential to develop methods capable of controlling the RTK activity with high temporal resolution. However, techniques for precisely modulating the activity of endogenous RTKs without requiring genetic modification remain insufficiently established. In this study, we developed a DNA aptamer agonist, Met-azo-aptamer, which enables reversible optical control of the activity of the c-Met receptor, a member of the RTK family. This was achieved by incorporating azobenzene, a photoisomerizable molecule, into a DNA aptamer that binds to c-Met. This design allows light-induced switching between the active and inactive structures of the aptamer. When the aptamer was applied to HeLa cells and exposed to ultraviolet or blue light, phosphorylation signals within the cells were activated in response to the light patterns. Furthermore, by variation of the light patterns, the Met-azo-aptamer successfully controlled the timing, amplitude, and duration of downstream ERK activation. The Met-azo-aptamer developed in this study offers a high-resolution method for investigating the relationship between RTK activation patterns and cell function or fate.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"41 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666711","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}
Chuanheng Ma, Yuan Ma, Hui Wang, Hongbo Wang, Mi Zhou, Guangtao Liu, Hanyu Liu, Yanming Ma
{"title":"Hydrogen-Vacancy-Induced Stable Superconducting Niobium Hydride at High Pressure","authors":"Chuanheng Ma, Yuan Ma, Hui Wang, Hongbo Wang, Mi Zhou, Guangtao Liu, Hanyu Liu, Yanming Ma","doi":"10.1021/jacs.4c15868","DOIUrl":"https://doi.org/10.1021/jacs.4c15868","url":null,"abstract":"In recent years, the discovery of unconventional polyhydrides under high pressure, including notable instances like CaH<sub>6</sub>, YH<sub>9</sub>, and LaH<sub>10</sub>, with superconducting critical temperature (<i>T</i><sub>c</sub>) above 200 K, has ignited considerable interest in the quest for high-temperature superconductivity in hydrogen-based materials. Recent studies have suggested the highly probable existence of hydrogen vacancies in these high-<i>T</i><sub>c</sub> superconducting hydrides, although there is no conclusive evidence. In this study, taking niobium (Nb) hydride as a model, we showcase the observation of nonstoichiometric face-centered cubic (<i>fcc</i>) NbH<sub>4-δ</sub> (δ∼0.23–0.51) at pressures ranging from 113 to 175 GPa, employing <i>in situ</i> high-pressure X-ray diffraction experiments in conjunction with first-principles calculations. Remarkably, our further analyses indicate that the hydrogen vacancies, along with the resulting configurational entropy, play crucial roles in stabilizing this nonstoichiometric <i>fcc</i> NbH<sub>4-δ</sub>. Electrical transport measurements confirmed the superconductivity, as evidenced by zero resistance as well as suppression of <i>T</i><sub>c</sub> with applying magnetic fields, with a <i>T</i><sub>c</sub> reaching up to 34 K. Our current results not only confirm the presence of hydrogen vacancies in high-<i>T</i><sub>c</sub> hydrides, but also provide key insights into the understanding of hydrogen-vacancy-induced stability for nonstoichiometric hydrides under high pressure.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"56 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666706","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}
Alessio Puggioli, Liyin Jiang, Ana G. Herraiz, Leonardo J. Nannini, Karen de la Vega-Hernández, Anxo Rey-Blanco, Alejandro Diéguez-Vázquez, Santiago Cañellas, Marcos G. Suero
{"title":"Late-Stage Photoredox-Catalyzed Aryl C–H Bond Diazomethylation with Atomic Carbon Reagents","authors":"Alessio Puggioli, Liyin Jiang, Ana G. Herraiz, Leonardo J. Nannini, Karen de la Vega-Hernández, Anxo Rey-Blanco, Alejandro Diéguez-Vázquez, Santiago Cañellas, Marcos G. Suero","doi":"10.1021/jacs.5c00045","DOIUrl":"https://doi.org/10.1021/jacs.5c00045","url":null,"abstract":"Herein, we present a novel class of diazo compounds as atomic carbon reagents substituted with two orthogonal redox-active leaving groups that were exploited in the late-stage construction of chiral centers with aryl C–H bonds from aromatic feedstocks and drug molecules. Key to the strategy was the use of photoredox catalysis to enable an initial C–H diazomethylation reaction able to generate diazomethyl-substituted redox-active esters. Subsequent construction of chiral centers with readily available starting materials proceeded using a broad range of well-known diazo and redox-active ester functionalizations. Moreover, the applicability of our novel atomic carbon reagent was tested in the automated parallel synthesis of a library of Fenofibrate derivatives.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"20 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Aqueous-S vs Organic-S Battery: Volmer-Step Involved Sulfur Reaction","authors":"Tengsheng Zhang, Yilong Zhao, Yutong Feng, Boya Wang, Yanyan Zhang, Xinran Li, Jiawei Liu, Wanhai Zhou, Wei Li, Xin Liu, Dongyuan Zhao, Dongliang Chao","doi":"10.1021/jacs.5c01727","DOIUrl":"https://doi.org/10.1021/jacs.5c01727","url":null,"abstract":"Aqueous-S batteries (ASBs) are emerging as promising energy storage technologies due to their high safety, low cost, and high theoretical energy density. However, the present understanding of sulfur evolution in water relies on experience derived from conventional organic electrolyte-based sulfur batteries (OSBs). The gap between ASB and OSB has impeded progress in advancing the rational design of sulfur catalysts in the aqueous phase. Herein, we reveal the unique interaction between H<sub>2</sub>O and S species, which is fundamentally distinguishable from the organic counterparts. A series of spectroscopy analyses discloses that elemental sulfur is initially reduced to polysulfides (mainly S<sub>4</sub><sup>2–</sup>), which subsequently react with H<sub>2</sub>O to generate HS<sup>–</sup>, involving both polysulfide conversion and the Volmer step of water dissociation. Combined electrochemical and computational analysis further proposes an aqueous-S catalyst selection metric based on simultaneous polysulfide adsorption and Volmer-step catalysis. As a proof of concept, we have successfully prioritized the Mo<sub>2</sub>C-catalyzed ASBs with a superior rate capability of 1040 mAh g<sup>–1</sup> than the Fe<sub>3</sub>C (693 mAh g<sup>–1</sup>) and pure C (510 mAh g<sup>–1</sup>) at a high current density of 5 A g<sup>–1</sup>. This work provides insights into the aqueous-S charge storage mechanism and establishes a foundational catalyst research paradigm for advancing the following ASBs.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"22 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666710","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}
Sara T. Gebre, Luis Martinez-Gomez, Christopher R. Miller, Clifford P. Kubiak, Raphael F. Ribeiro, Tianquan Lian
{"title":"Fano Resonance in CO2 Reduction Catalyst Functionalized Quantum Dots","authors":"Sara T. Gebre, Luis Martinez-Gomez, Christopher R. Miller, Clifford P. Kubiak, Raphael F. Ribeiro, Tianquan Lian","doi":"10.1021/jacs.4c14499","DOIUrl":"https://doi.org/10.1021/jacs.4c14499","url":null,"abstract":"Molecular catalyst functionalized semiconductor quantum dots (QDs) are a promising modular platform for developing novel hybrid photocatalysts. The interaction between adsorbed catalyst vibrations and the QD electron intraband absorption can influence the photophysical properties of both the QD and the catalysts and potentially their photocatalysis. In CdSe QDs functionalized by the CO<sub>2</sub> reduction catalyst, Re(CO)<sub>3</sub>(4,4’-bipyridine-COOH)Cl, we observe that the transient Fano resonance signal resulting from coupling of the catalyst CO stretching mode and the QD conduction band electron mid-IR intraband absorption appears on an ultrafast time scale and decays with the electron population, irrespective of the occurrence of photoreduced catalysts. The Fano asymmetry factor increases with an increase in the adsorbed catalyst number and a decrease in QD sizes. The latter can be attributed to an enhanced charge transfer interaction between the more strongly quantum-confined QD conduction band and catalyst LUMO levels. These results provide a more in-depth understanding of interactions in excited QD-catalyst hybrid photocatalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Competition between Hydrogen and Chalcogen Bonding in Homodimers of Chalcogen Hydrides (H2X)2, X = O, S, Se, Te","authors":"Maxwell P. Hoffman, Sotiris S. Xantheas","doi":"10.1021/jacs.4c17428","DOIUrl":"https://doi.org/10.1021/jacs.4c17428","url":null,"abstract":"The structural and chemical bonding motifs manifested by the competition between hydrogen and chalcogen bonding in the homodimers of chalcogen hydrides (H<sub>2</sub>X)<sub>2</sub>, where X = O, S, Se, Te have been characterized using high-level electronic structure calculations and analysis of the electron density based on Quasi-atomic orbital (QUAO) and the Symmetry-adapted perturbation theory (SAPT) methods. The QUAO analysis clearly identifies a three-center interaction responsible for either hydrogen or chalcogen bonds: in the former, the σ-bond connecting the donor and hydrogen atom participating in the hydrogen bond interacts with the lone pair on the nucleophile acceptor via the hydrogen atom, while in the latter this same σ-bond interacts with the nucleophile lone pair via the donor chalcogen. The number of minimum energy structures increase dramatically from one for (H<sub>2</sub>O)<sub>2</sub>, three for (H<sub>2</sub>S)<sub>2</sub>, four for (H<sub>2</sub>Se)<sub>2</sub>, and finally six for (H<sub>2</sub>Te)<sub>2</sub>. The emergence of the chalcogen-bonded arrangements appears for (H<sub>2</sub>S)<sub>2</sub> with their subsequent energetic stabilization over the hydrogen-bonded minima manifesting in (H<sub>2</sub>Se)<sub>2</sub> and (H<sub>2</sub>Te)<sub>2</sub>. In particular, one of the (H<sub>2</sub>S)<sub>2</sub> , two of the (H<sub>2</sub>Se)<sub>2</sub>, and three of the (H<sub>2</sub>Te)<sub>2</sub> dimers are chalcogen bonded. Induction plays a small but important role in stabilizing hydrogen over chalcogen-bonded structures, while dispersion is more important for chalcogen bonds.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"34 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666709","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}
Mia D. Stankovic, Bowen Ge, Jessica F. Sperryn, Curtis P. Berlinguette
{"title":"Electrochemical Control of Heterolytic and Homolytic Hydrogenation Pathways at a Palladium Surface","authors":"Mia D. Stankovic, Bowen Ge, Jessica F. Sperryn, Curtis P. Berlinguette","doi":"10.1021/jacs.4c14671","DOIUrl":"https://doi.org/10.1021/jacs.4c14671","url":null,"abstract":"Here, we use a palladium membrane reactor to investigate hydrogen transfer pathways at the palladium surface. The palladium membrane reactor uses electrochemistry to facilitate the controlled adsorption of hydrogen, sourced from water, into one face of the palladium membrane. This hydrogen permeates through palladium and reacts with unsaturated species in the opposing chamber. The amount of hydrogen loaded into the palladium can be controlled electrochemically to form a well-defined and static PdH<sub><i>x</i></sub> ratio for studying chemical hydrogenation. These static PdH<sub><i>x</i></sub> ratios are otherwise difficult to achieve. We show a preference for homolytic hydrogen transfer pathways at lower current densities and heterolytic hydrogen transfer pathways at higher current densities. We also show reaction conditions that favor hydrogen reacting as either a hydrogen radical (H<sup>•</sup>), a proton (H<sup>+</sup>), or a hydride (H<sup>–</sup>).","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"24 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672748","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}
Hang Zhou, Tomasz K. Piskorz, Keyu Liu, Yining Lu, Fernanda Duarte, Paul J. Lusby
{"title":"Dissecting the Effects of Cage Structure in the Catalytic Activation of Imide Chlorenium-Ion Donors","authors":"Hang Zhou, Tomasz K. Piskorz, Keyu Liu, Yining Lu, Fernanda Duarte, Paul J. Lusby","doi":"10.1021/jacs.5c01249","DOIUrl":"https://doi.org/10.1021/jacs.5c01249","url":null,"abstract":"Imide-based chlorinating reagents are mild and easy to use yet can lack the reactivity of charged chlorenium-ion donors. Here, we present a simple strategy for increasing the reactivity of these neutral chlorinating species by encapsulation inside a cationic coordination cage. Using this approach, we demonstrate that two different-sized Pd<sub>2</sub>L<sub>4</sub> cages can catalyze chlorolactonization and chlorocycloetherification reactions of acid and alcohol functionalized α and β-substituted styrene substrates with either 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) or <i>N</i>-chlorosuccinimide (NCS) as the chlorenium sources. A kinetic study shows that the cages are proficient catalysts with a significant acceleration up to 10<sup>5</sup>. However, an unexpected dichotomy is revealed wherein the smaller cage, which is best preorganized to bind and nominally provide maximum activation of the imide reagent, shows an order of magnitude less acceleration than the larger cage that has apparently mismatched host–guest chemistry. When the scope of reactions is further extended to the chlorination of simple, unfunctionalized α-methylstyrene, the same pattern of cage reactivity is observed, suggesting that differences are not explained by coencapsulation. Computational studies indicate that the trend in reactivity is caused by the transition state being less fixed in the larger cage, allowing it to find optimal binding and thereby generate stronger interactions. This investigation highlights the importance of understanding the underlying mechanisms of cage reactivity to design new noncovalent catalysts for a greater range of transformations.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"92 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666708","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}