化学•材料最新文献

{"title":"Influence of Dissolved Iron in Solution on MgO Hydroxylation and Carbonation","authors":"Juliane Weber, Brittany Moseley, Ke Yuan, Barbara R. Evans, Vitalii Starchenko, Elena Tajuelo Rodriguez, Dong Youn Chung, Matthew G. Boebinger, Michael A. McGuire, George Yumnam, Raphael P. Hermann, Lawrence M. Anovitz, Andrew G. Stack","doi":"10.1021/acs.jpcc.4c04953","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04953","url":null,"abstract":"MgO (periclase) is a promising material for direct air capture of CO₂ using a mineral looping process, but it is unknown how impurities in the environment will affect the CO₂ uptake and hence process economics. Here, we investigated the effects of dissolved iron on the extents of MgO hydroxylation and subsequent carbonation reactions to determine if this has a beneficial or detrimental effect. On single-crystal MgO, dissolved iron prevented hydration of MgO to Mg(OH)₂ (brucite) and instead formed a shell of lepidocrocite (γ-FeOOH). This did not passivate the MgO as dissolution below the shell was observed. During hydroxylation of MgO powders in the presence of dissolved iron, formation of brucite containing Fe(II) was observed. In addition, formation of nanoscale iron oxides containing Fe(III) was observed using magnetometry and Mössbauer spectroscopy. Subsequent carbonation experiments showed increased carbonation of MgO hydroxylated in the presence of iron. Our results indicate that the presence of dissolved solute impurities during hydroxylation may be beneficial for carbonation of hydroxylated MgO.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"111 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine Learning Mapping Approach for Computing Spin Relaxation Dynamics","authors":"Mohammad Shakiba, Adam B. Philips, Jochen Autschbach, Alexey V. Akimov","doi":"10.1021/acs.jpclett.4c03293","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03293","url":null,"abstract":"In this work, a machine learning mapping approach for predicting the properties of atomistic systems is reported. Within this approach, the atomic orbital overlap, density, or Kohn-Sham (KS) Fock matrix elements obtained at a low level of theory such as extended tight-binding have been used as input features to predict the electric field gradient (EFG) tensors at a higher level of theory such as those obtained with hybrid functionals. It is shown that the machine-learning-predicted EFG tensors can be used to compute spin relaxation rates of several ions in aqueous solutions. From only a fraction of data used in direct calculation, one can predict the quadrupolar isotropic spin relaxation rates with good accuracy, achieving relative errors between about 2–8% for different ions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"268 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Naphthalene Hydrodearomatization via Controllable Photocatalytic Hydroboration","authors":"Wengang Xu, Juan Tao, Yu-Qi Wang, Mingrui Liu, Fengyu Ma, Qiao Zhang, Feng-Lian Zhang, Mingbo Wu","doi":"10.1021/acs.joc.4c02732","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02732","url":null,"abstract":"The photocatalytic dearomative 1,4-hydroboration of naphthalenes with an N-heterocyclic carbene borane (NHC-BH₃) complex was reported herein with controllable regioselectivity and chemoselectivity. This protocol yielded a wide range of naphthalene derivatives bearing various functional groups, notably bioactive compounds. Hydroboration occurred through the cooperation of photoredox and hydrogen atom transfer via boryl radical addition to naphthalene and further selective protonation. Notably, tuning the conditions could lead to further hydrogenation of the tetrahydroboration products. Mechanistic studies, including experimental and computational studies, elucidated the mechanism for the regioselectivity.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"24 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dehydrogenative Coupling of Alcohols with Hydrazines under Nickel Catalysis","authors":"Reshma Babu, Abhijith Karattil Suresh, Rohit Kumar, Ekambaram Balaraman","doi":"10.1021/acs.joc.4c02279","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02279","url":null,"abstract":"The development of efficient and robust catalytic systems based on earth-abundant transition metals for fundamentally new transformations is crucial for sustainable chemical synthesis. Herein, an effective and selective Ni-catalyzed dehydrogenative coupling of alcohols with hydrazines with the liberation of ammonia gas is reported. Although several methods were documented for the <i>N</i>-alkylation reaction, the present strategy is conceptually novel, and the reaction proceeds through a pathway involving N–N bond cleavage of phenylhydrazine followed by hydrogen autotransfer. This unprecedented method demonstrates a wide substrate scope, allowing for the synthesis of C–N coupled products from arylhydrazines using various types of alcohols, including aryl, fused aryl, heteroaromatic, cyclic, and aliphatic alcohols, both primary and secondary alcohols. The present catalytic approach was expanded to facilitate selective deuterium incorporation reactions by employing deuterated alcohols at the α-methyl position of the resulting <i>N</i>-alkylated products. It is noteworthy that we have broadened the applicability of the current catalytic systems to facilitate the ketazine synthesis of hydrazine monohydrate by employing secondary alcohols. The reaction utilizes an inexpensive, abundant, and renewable alcohol that serves as both an alkylating and (transfer) hydrogenating agent. Kinetic studies reveal that the reaction rate depends on the concentration of arylhydrazine and the nickel catalyst, following fractional order.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"148 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conformational Analysis of Swallowtail Motifs in Porphyrins","authors":"Phuong-Lien Doan Cao, Khiem Chau Nguyen, Alexander A. Nevzorov, Milena Jovanovic, Phattananawee Nalaoh, Jonathan S. Lindsey","doi":"10.1021/acs.joc.4c02059","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02059","url":null,"abstract":"Aqueous solubilization of porphyrins, often accomplished with appended polar aryl groups, can also be achieved with symmetrically branched alkyl (i.e., swallowtail) groups terminated with polar moieties. Here, carboxylic acids are employed as termini (versus prior phosphono- or phosphoester termini) in designs of <i>trans</i>-AB-porphyrins bearing a single swallowtail group (A) or <i>trans</i>-A₂-porphyrins bearing two swallowtail groups. Variable-temperature ¹H NMR studies (−60 to 97 °C) revealed that the 4-heptanedioic acid group at the meso-position of the free base porphyrin rotates with rate constant 5 s^–1 (310 K) and Arrhenius energy barrier <i>E</i>_a = 11.5 kcal/mol, whereas an isopropyl group undergoes rotation ∼1000-times faster (<i>k</i> = 5770 s^–1). The interconversion is sufficiently fast that conformational diastereomers, as when two such swallowtail groups are present in a <i>trans</i>-A₂-porphyrin, would not be isolable at room temperature (Class I atropisomers). DFT calculations (4 porphyrins containing the isopropyl or 4-heptanedioic acid groups) showed that the lowest energy conformer contains the swallowtail C–H unit in the plane of the porphyrin. The presence of one or two 4-heptanedioic acid moieties imparted solubility of the porphyrin in phosphate-buffered saline (PBS). The results suggest applications in the life sciences where compact, aqueous-soluble porphyrins are desired.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"114 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of Aminated C-3 Aryloylated Benzofuran, Furopyridine, Benzothiophene, and Indole Derivatives from 1,6-Enyne and N-Aminopyridinium Salt in Visible Light","authors":"Shruti Rajput, Rajat, Nitesh, Priya Gupta, Harpal Singh, Nidhi Jain","doi":"10.1021/acs.joc.4c02439","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02439","url":null,"abstract":"We report a visible-light-assisted tandem oxidative 5-<i>exo</i>-dig cyclization of 1,6-enynes for the synthesis of aminated C-3 aryloylated benzofuran, furopyridine, benzothiophene, and indole derivatives. The nitrogen-centered radical generated in situ from <i>N</i>-aminopyridinium salt initiates the consecutive formation of C–N, C–C, and C–O bonds. The methodology exhibits good functional group tolerance and regioselectivity, furnishing products in good to excellent yields at room temperature. Preliminary biological screening of synthesized molecules reveals their potential as anticancer agents.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"31 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the Origin of the Redox Potential Shift of Transition Metal in LiFexMn1–xPO4 Cathodes by the Molecular Orbital Theory","authors":"Zhenming Xu, Yuqiao Jiang, Xiangmin Feng, Ke Wang, Yue Zhou, Mingbo Zheng, Yixi Lin, Yinghui Xia, Zhenhui Liu, Laifa Shen, Yongyao Xia","doi":"10.1021/acs.jpcc.4c06546","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06546","url":null,"abstract":"Olivine-structured LiFe_<i>x</i>Mn_1–<i>x</i>PO₄ cathodes exhibiting higher redox potentials than their layer oxide counterparts have been utilized in commercial lithium-ion batteries, but the origin of the systematical shifts of the redox potential of transition metal couples with the variation of the Fe–Mn molar ratio is not clear, at least on the electronic scale. In the current work, we carried out experiments and theoretical calculations to study the molecular orbital characteristics of metal–ligand and determined the origin of transition metal redox potential shifts in LiFe_1–<i>x</i>Mn_<i>x</i>PO₄ cathodes on the electronic scale. The systematic shifts of redox potential of Fe³⁺/Fe²⁺ and Mn³⁺/Mn²⁺ couples in LiFe_1–<i>x</i>Mn_<i>x</i>PO₄ cathodes are not only because of the decreased energies of e_g* antibonding orbitals with regard to the enlarged metal–ligand atomic distances but also due to almost the same slopes of the e_g* antibonding orbital energies as a function of atomic distance. This chemistry picture of the metal–ligand atomic distance-dependent e_g bonding/e_g* antibonding splitting provides a new perspective to understand the redox potential variations of the electrode upon element substitution.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"30 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-Dependent Reaction Kinetics of the Carbanions C_<i>n</i>^- and C_<i>n</i>H^- (<i>n</i> = 2 and 4) with H Atoms in a Cryogenic Ion Trap.","authors":"Christine Lochmann, Sruthi Purushu Melath, Michael Hauck, Robert Wild, Roland Wester","doi":"10.1021/acs.jpca.4c06626","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c06626","url":null,"abstract":"<p><p>We report on the temperature-dependent reactions of the carbon-chain anions C₂^- and C₄^-, as well as the hydrocarbons C₂H^- and C₄H^- with H atoms in the temperature regime between 8 and 296 K. The experiments have been carried out in a temperature-variable radiofrequency multipole ion trap. From the measured kinetics, we have derived reaction rate coefficients that are constant for all considered systems in the measured temperature regime. For the C₂^-, C₄^-, and C₄H^- anions, the values are about a factor of 2 smaller than the Langevin capture rate coefficient, while for C₂H^-, the measured value agrees with the Langevin value. No theoretical calculations are available at present to explain this. All rate coefficients are in good agreement with previous measurements at room temperature.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Method for Determining the Excess Chemical Potential Using Liquid-Vapor Phase Coexistence Simulations.","authors":"Andrew M Fadgen, Nicholas A Pizzi, Rodney J Wigent, Preston B Moore","doi":"10.1021/acs.jpcb.4c07206","DOIUrl":"https://doi.org/10.1021/acs.jpcb.4c07206","url":null,"abstract":"<p><p>Molecular dynamics simulations are a powerful tool for probing and understanding the theoretical aspects of chemical systems and solutions. Our research introduces a novel method for determining the excess chemical potential of non-ideal solutions by leveraging the equivalence between the chemical potential of the vapor phase and liquid phase. Traditional approaches have relied on bulk simulations and the integration of pair distribution functions (<i>g</i>(<i>r</i>)), which are computationally intensive to obtain accurate results. In contrast, our method utilizes a liquid-gas system, where determining the vapor pressure allows for a quick and accurate calculation of the excess chemical potential relative to a reference system, e.g., pure solvent. This approach significantly reduces computational effort while maintaining high accuracy and precision. We demonstrate the effectiveness of this method using a simplified Lennard-Jones model, although the method is broadly applicable to a wide range of systems, including those with complex interactions, varying concentrations, and different temperatures. The reduced computational demands and versatility of our approach make it a valuable tool for studying non-ideal solutions, including ionic solutions in molecular simulations.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Conductive Dynamics of Sb2(S,Se)3-Based Memristors for Non-Volatile Memory and Neuromorphic Applications","authors":"Yuanjie Yang, Yuanhui Yang, Lei Zheng, Yuchan Wang, Fang Wang, Xiaolei Li, Liangliang Feng, Hongling Guo, Shifu Xiong, Kailiang Zhang","doi":"10.1021/acs.jpclett.4c03367","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03367","url":null,"abstract":"Advancing the development of novel materials or architectures for random access memories, coupled with an in-depth understanding of their intrinsic conduction mechanisms, holds the potential to transcend the conventional von Neumann bottleneck. In this work, a novel memristor based on the Sb₂(S,Se)₃ material with an alloy of S and Se was fabricated. A systematic investigation of the correlation between the Se/(S + Se) ratio and memristive performance revealed that Ag/Sb₂(S,Se)₃/FTO memristive behavior is uniquely associated with the formation and disruption of anion vacancies and silver filaments. The resultant Ag/Sb₂(S,Se)₃/FTO memristor devices demonstrated good resistive switching, with durability surpassing 3 × 10⁴ cycles, showcasing multilevel conductivity states. Furthermore, these devices successfully emulated the synaptic functionality. This research has established the foundation for the intrinsic conduction mechanisms of antimony chalcogenide memristor artificial synapses.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"79 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}