化学最新文献

{"title":"Theoretical and Experimental Insights into the Chemical Properties of L-Alanine (2-Aminopropionic Acid)","authors":"Abdul Nazar P. V.,&nbsp;Amna Sherin T.,&nbsp;Sandhya Savita,&nbsp;Mudassar Shahid,&nbsp;Abdullah Alarifi,&nbsp;Nazia Siddiqui,&nbsp;Saleem Javed,&nbsp;Akhilesh Kumar,&nbsp;Simant Kumar Srivatava","doi":"10.1002/slct.202500367","DOIUrl":"https://doi.org/10.1002/slct.202500367","url":null,"abstract":"<p>This study deals with the properties of 2-aminopropionic acid (APPA), an amino acid, using a powerful combination of theory and experiment. We employ computational tools to predict its structure and reactivity, revealing its most stable conformation and potential reaction sites. DFT theory was employed using the software “Gaussian 09W” and “Gauss-View 5.0′ with the ‘B3LYP/6–311++G(d,p)” basis set for DFT calculations. The optimized structure of 2-aminopropionic acid was determined from a variety of conformations, and their associated values were obtained. Analyzing the optimized geometry allowed for identifying the parameters of the stable conformation of 2-aminopropionic acid. Additionally, 2-aminopropionic acid was experimentally investigated by employing FTIR and UV–visible spectroscopic methods. The experimentally gained values were correlated with the theoretical values obtained from the DFT calculations. Molecular electrostatic potential analysis was utilized to identify reactive sites and predict chemical reactivity, whereas electron localization function analysis provided insights into electron distribution. Additionally, we analyzed promising nonlinear optical properties, hinting at future applications. We also studied 2-aminopropionic acid's potential for pharmaceutical development, revealing its drug-like nature. This study further explores 2-aminopropionic acid's fascinating properties and paves the way for potential drug development.</p>","PeriodicalId":146,"journal":{"name":"ChemistrySelect","volume":"10 23","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Identification of IMP and VIM Metallo-β-Lactamases in Gram-Negative Bacteria Using A-MALDI","authors":"Dong Huey Cheon,&nbsp;Seohyun Hwang,&nbsp;Yoon Kyung Choi,&nbsp;Saeyoung Lee,&nbsp;Won Suk Yang,&nbsp;Bo Kyung Kim,&nbsp;Min Jin Kim,&nbsp;Sun Hwa Lee,&nbsp;Je-Hyun Baek","doi":"10.1002/rcm.10095","DOIUrl":"https://doi.org/10.1002/rcm.10095","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Rapid and accurate identification of carbapenemase-producing Enterobacteriaceae (CPE) is crucial for effective infection control and patient treatment. However, accurate identification of VIM and IMP metallo-β-lactamases remains still challenging using MALDI-TOF MS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The A-MALDI method which incorporates sequential lysis steps and internal mass calibration, was used for the identification of IMP and VIM carbapenemases. Two <i>Escherichia coli</i> standard strains and 26 clinical isolates harboring IMP or VIM genes were tested by A-MALDI along with corresponding negative controls. Previously published carbapenemases-negative data (<i>n</i> = 112) were used to check the specificity of IMP and VIM identification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For IMP-positive isolates, proteoforms corresponding to amino acid residues 20–246 showed distinct peaks for IMP. For VIM-positive isolates, unique single peaks corresponding to amino acid residues 27–266 allowed clear identification of VIM. Clinical evaluation of A-MALDI demonstrated 93.9% accuracy for IMP identification (100% sensitivity, 93.3% specificity) and 100% accuracy for VIM identification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study successfully expands the direct identification capabilities for VIM and IMP, achieving comprehensive identification of all six carbapenemases using A-MALDI. We anticipate that A-MALDI will provide clinical laboratories with a powerful tool for rapid identification of all types of carbapenemases in bacterial infections.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 19","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300299","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":"Cover Feature: Cu-Ln (Ln = Gd, Eu, Sm) Dinuclear Complexes Based on Schiff Base o-van-en Ligand: Syntheses, Crystal Structures, and Magnetic Properties","authors":"Andrea Koščíková,&nbsp;Juraj Černák,&nbsp;Larry R. Falvello,&nbsp;Milagros Tomás,&nbsp;Irene Ara,&nbsp;Ján Titiš,&nbsp;Roman Boča","doi":"10.1002/chem.202583402","DOIUrl":"https://doi.org/10.1002/chem.202583402","url":null,"abstract":"<p><b>In analogy to a polypod crustacean</b>, a metalloligand centred on the stable, simple five-coordinate Cu pyramid embraces a lanthanoid centre, which has a more complex eight-coordinate environment. For Ln = Gd and Eu, the product exhibits field-supported slow magnetic relaxation. More information can be found in the Research Article by J. Černák, I. Ara and co-workers (DOI: 10.1002/chem.202500376).\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":144,"journal":{"name":"Chemistry - A European Journal","volume":"31 34","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chem.202583402","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300275","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}

{"title":"Design of Multi-Interface Hydrogenated Yolk–Shell C@TiO2 Microspheres With Enhanced Microwave Absorption Performances","authors":"Jun Quan,&nbsp;Zhuoying Li,&nbsp;Xuming Wu,&nbsp;Lei Zhao,&nbsp;Chunhua Tian","doi":"10.1002/aoc.70259","DOIUrl":"https://doi.org/10.1002/aoc.70259","url":null,"abstract":"<div>\u0000 \u0000 <p>Rational design on the microstructure and chemical composition is a feasible strategy to boost the performance of some conventional microwave absorbers. In this study, we designed and synthesized unique hydrogenated yolk–shell C@TiO₂ composites (C@TiO₂-H₂). The results indicate that the as-prepared composite can effectively modify the matching degree of characteristic impedance and dielectric loss property by high complex permittivity carbon cores, crystal/disorder microstructure of TiO₂ shells, and yolk–shell microstructure. The maximum reflection loss is −76.8 dB at 7.6 GHz with an absorber thickness of 3.0 mm. With an absorber thickness of 2.0 mm, the bandwidth over −10.0 dB is 4.5 GHz from 10.7 to 15.2 GHz. Notably, C@TiO₂-H₂ outperformed TiO₂, hydrogenated TiO₂ (TiO₂-H₂), carbon microspheres (C_m), as well as unhydrogenated yolk–shell C@TiO₂ (C@TiO₂-N₂) microspheres, where superior reflection loss and wide response bandwidth can be achieved simultaneously. Therefore, the yolk–shell C@TiO₂-H₂ microspheres are expected to be promising candidates for microwave absorption applications.</p>\u0000 </div>","PeriodicalId":8344,"journal":{"name":"Applied Organometallic Chemistry","volume":"39 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300278","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":"The effect of alkyl termination on the optical and electronic properties of silicon nanoparticles†","authors":"Eimear Madden and Martijn A. Zwijnenburg","doi":"10.1039/D5RA03272E","DOIUrl":"https://doi.org/10.1039/D5RA03272E","url":null,"abstract":"<p >In this study, we use a combination of (time-dependent) density functional theory and many-body perturbation theory methods to study the impact of alkyl termination on the optical and electronic properties of silicon nanoparticles (SiNPs), as well as the effect of increasing particle size. A comparative study of hydrogen and methyl-terminated SiNPs reveals that replacing hydrogen atoms with methyl groups results in a reduction of the fundamental gap, optical gap, and exciton binding energy. The effect of replacing hydrogen by methyl diminishes with the increasing size of the silicon core of the particles, which can be attributed to the decreasing surface-to-volume ratio. Larger hydrogen-terminated SiNPs, therefore, serve as increasingly accurate models for alkyl-terminated SiNPs. The size of the lowest energy excited-state (exciton) increases when replacing (more of the) hydrogen atoms with methyl groups for a given silicon core size, suggesting that the exciton delocalises onto the methyl groups. Analysis of the relevant natural transition orbitals confirms that both the excited electron and hole components of the exciton partially delocalise on to the methyl groups, with increased delocalisation in the case of the excited electron. The reduced fundamental and optical gaps and exciton binding energy in methyl-terminated SiNPs, and probably by extension alkyl terminated SiNPS in general, are likely due to the electron-donating nature of methyl groups combined with exciton delocalisation.</p>","PeriodicalId":102,"journal":{"name":"RSC Advances","volume":" 26","pages":" 20453-20463"},"PeriodicalIF":3.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ra/d5ra03272e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of new thorium nuclear clock materials based on polyatomic ions","authors":"Harry William Toriel Morgan, Hoang Bao Tran Tan, Andrei Derevianko, Ricky Elwell, James Terhune, Eric R Hudson, Anastassia Alexandrova","doi":"10.1039/d5dt00736d","DOIUrl":"https://doi.org/10.1039/d5dt00736d","url":null,"abstract":"Compounds of polyatomic anions are investigated theoretically as hosts for thorium in nuclear clock devices. The 229Th nucleus has an excited state at 8.355 eV which can be reached using a VUV laser as demonstrated in recent experiments. Incorporating 229Th into a host crystal is an essential step towards developing an ultra-stable nuclear clock. To be a suitable host, a material must have a band gap larger than the nuclear transition frequency. Thus, most research to date has focused on fluorides like LiSrAlF6 and CaF2, for they feature ionic bonding and large band gaps. However, ionicity of chemical bonding can be pushed to its limits by use of superhalogens - polyatomic anions whose electron affinity can be greater than that of the halogens. An additional concern for fluorides is the presence of 19F nuclear spins in the material that can couple to the spin of the 229Th, detrimental to clock performance. In this work we investigate salts containing superhalogen anions, with the goal of identifying promising new hosts for 229Th clocks. Specifically, we investigate compounds of Ca, Sr, and Ba with three anions - [BF4]-, [ClO4]-, and [SO4]2-. By computing the electronic properties of the pure and thorium-doped materials, we predict that M(BF4)2 have the widest band gaps, making them a promising materials class. On the other hand, MSO4 could produce the most accurate clocks by eliminating inhomogeneous broadening due to nuclear spin interactions. These results may guide experimental searches for new 229Th clock materials and offer new opportunities to study this unique nuclear transition in the solid state.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"229 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144304474","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":"Electroanalysis of Meat Discoloration: Beef Sarcoplasm Extract with Storage Time","authors":"Silan Bhandari, Sachinthani A. Devage, Rishav Kumar, Ranjith Ramanathan, Sadagopan Krishnan","doi":"10.1039/d5an00301f","DOIUrl":"https://doi.org/10.1039/d5an00301f","url":null,"abstract":"Electrochemical techniques offer a promising approach to monitor redox-active biomolecules involved in meat discoloration. Building on our previous identification of characteristic redox peaks in beef extracts associated with myoglobin oxidation (J. Am Chem. Soc., 2024, 146, 30728–30732, DOI: 10.1021/jacs.4c09375), we present an extended investigation into electrochemical changes over longer meat storage time. Square wave voltammetry revealed frequency-dependent peak potential shifts over 9 days, indicative of a quasi-reversible electron transfer process. Spiking experiments with purified myoglobin in the meat extract confirmed its predominant contribution to the observed voltammetric signals. After 9 days of storage, peak currents at −0.26 V (redox-active myoglobin heme center) and +0.38 V (overall oxidation of meat components) increased by 68.9% and 270.3%, respectively, compared to relative changes of 37.3% and 61.7% in a shorter-duration study. These electrochemical findings showed a strong correlation with spectrophotometrically determined metmyoglobin accumulation (r = 0.98, P &lt; 0.001). The results provide insight into redox transformations during meat spoilage and contribute to the development of electrochemical tools for meat quality evaluation.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"43 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144304477","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":"Imine-Oxazoline (ImOx): A C1-Symmetric N,N-Bidentate Ligand for Asymmetric Catalysis","authors":"Elliot S. Silk, Haozhe Zhu, Alexander G. Shtukenberg, Tianning Diao","doi":"10.1021/acscatal.5c03134","DOIUrl":"https://doi.org/10.1021/acscatal.5c03134","url":null,"abstract":"Asymmetric catalysis relies on the design of chiral ligands, but the variety of nitrogen-based ligands remains limited. To address this gap, we have developed a class of <i>C</i>₁-symmetric <i>N</i>,<i>N</i>-bidentate ligands, imine-oxazoline (ImOx), derived from amino acids through a four-step synthesis. ImOx features an imine moiety conjugated with a chiral oxazoline ring as a hybrid of α-diimine (ADI) and pyridine oxazoline (PyOx) ligands. Its low symmetry allows for independent optimization at both coordination sites. ImOx improves the enantioselectivity of palladium-catalyzed conjugate addition reactions, demonstrating a strong correlation between ee and the steric effects on both the imine and oxazoline sites. Studies on well-defined organopalladium intermediates reveal that the steric bulk of ImOx necessitates a cationic pathway to promote alkene insertion. Structural characterization of ImOx suggests a stronger <i>trans</i>-influence compared to PyOx. Moreover, ImOx demonstrates versatile redox activity, promoting the reduction of nickel complexes and stabilizing nickel radical complexes. We anticipate that ImOx will expand the toolkit of chiral N-ligands for asymmetric catalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"21 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305268","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":"Metal Ion Isotope Ratio Using ESI-Orbitrap HRMS: Proof of Concept and Initial Performance Evaluation for Lead Isotopic Ratios","authors":"Gianluca Roncoroni, Davide Spanu, Gilberto Binda, Damiano Monticelli","doi":"10.1021/acs.analchem.5c01033","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c01033","url":null,"abstract":"This study introduces a novel approach using an electrospray source coupled to an Orbitrap MS instrument to determine metal isotope ratios. The procedure involves forming a complex between the ion of interest and an appropriate ligand, generating gas-phase ions via electrospray ionization, selecting the complex mass by quadrupole filtering, and performing collisional fragmentation to yield free metal ions. The isotopic pattern of the free ion is then analyzed by high-resolution MS. The approach ensures high selectivity and interference-free spectra. A proof-of-concept study was conducted to determine Pb isotope ratios, focusing on identifying the factors that influence the accuracy and precision of the procedure. At this early stage, optimal accuracy was achieved even in the presence of matrix components by applying mass bias correction methods originally developed for other isotope ratio techniques; precision is comparable to that achieved by single-collector ICP-MS instrumentation. This approach may complement conventional methods that suffer from limited mass resolution and usually require extensive sample preparation.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"51 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305391","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":"Synergistic Photoredox and High-Spin Cobalt Cluster Dual Heterogeneous Catalysis: Visible-Light-Driven C(sp2)–H Bond Functionalization","authors":"Ashish Kumar Dhara, Song-Song Bao, Ye-Hui Qin, Li-Min Zheng","doi":"10.1021/acs.inorgchem.5c00763","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.5c00763","url":null,"abstract":"We report visible-light-driven C(sp²)–H functionalization of indoles with naphthoquinone using a dual photocatalytic system of Eosin Y and a high-spin cobalt cluster. This one-pot transformation provides efficient access to a variety of pharmaceutically relevant heterocycles from readily available indoles under chemical oxidant-free and environmentally benign conditions. The reaction scope is further extended to the cyclization of aromatic amines, yielding amination products in moderate to good yields. Mechanistic investigations reveal that the formation of 3-indolylquinone proceeds via a single-electron transfer (SET) mechanism, followed by hydrogen atom transfer (HAT), with radical intermediates clearly detected by EPR spectroscopy. Moreover, the cooperative interactions between the cobalt centers enhance the catalytic efficiency, offering advantages over the mononuclear cobalt catalyst. This work introduces a novel approach for selective C–H functionalization through metallaphotoredox catalysis and expands its potential applications in organic synthesis.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":"605 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305418","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}