Helvetica Chimica Acta最新文献_第5页

Introduction for the Special Collection in the Honor of Scott Denmark 为纪念史考特·丹麦而特别收藏的介绍

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-30 DOI: 10.1002/hlca.202400183

Jeffrey Bode, Cathleen Crudden

引用次数: 0

Synthesis of α-Fluoroketones from Carboxylic Acids via Decarboxylation of Fluorinated Malonates 氟化丙二酸酯脱羧法由羧酸合成α-氟酮

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-29 DOI: 10.1002/hlca.202400187

Raffael Davenport, Rolandas Cibiras, Gabriel Schäfer

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Effect of Particle Size and Alloying with Gallium and Zinc in Copper Nanoparticles from Ab Initio Molecular Dynamics 从从头算分子动力学看铜纳米颗粒尺寸及镓锌合金化的影响

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-24 DOI: 10.1002/hlca.202400124

Andreas Müller, Aleix Comas-Vives, Christophe Copéret

{"title":"Effect of Particle Size and Alloying with Gallium and Zinc in Copper Nanoparticles from Ab Initio Molecular Dynamics","authors":"Andreas Müller, Aleix Comas-Vives, Christophe Copéret","doi":"10.1002/hlca.202400124","DOIUrl":"https://doi.org/10.1002/hlca.202400124","url":null,"abstract":"Supported nanoparticles (NPs) are an intense field of research in industry and academia due to their unique catalytic properties. Yet, establishing relationships between structure and activity is challenging due to multiple possible compositions, interfaces, and alloy formation. This is especially pronounced for bimetallic NPs used in the CO2-hydrogenation-to-methanol, where the structure responds dynamically to the chemical potential of the reactants and products, resulting in distinct surface structures depending on the exact reaction conditions. These phenomena have been highlighted by combining ab initio Molecular Dynamics (AIMD) and Metadynamics (MTD) with in situ X-ray absorption spectroscopy, chemisorption, and CO-IR. Here, we aim to understand how particle size and simulation temperature influence the structure and dynamics of small Cu NPs using the diffusion coefficients and the radial distribution function/atomic pair density function as descriptors using AIMD simulations. We found that decreasing the particle size or increasing the simulation temperature results in increased atom mobility, highlighted by the increased metal diffusion and resulting in reduced particle crystallinity. We also find that alloying Cu with Ga significantly increases the diffusion of both elements in the particle compared to the monometallic ones. In contrast, such diffusion lies in between the individual elements composing the CuZn particles.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structure and Magnetic Properties of a Series of Uranium Bis-Siloxide Complexes 一系列铀铋-硅氧化物配合物的结构和磁性能

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-23 DOI: 10.1002/hlca.202400189

Luciano Barluzzi, Ivica Zivkovic, Farzaneh Fadaei-Tirani, Rodolphe Clérac, Marinella Mazzanti

{"title":"Structure and Magnetic Properties of a Series of Uranium Bis-Siloxide Complexes","authors":"Luciano Barluzzi, Ivica Zivkovic, Farzaneh Fadaei-Tirani, Rodolphe Clérac, Marinella Mazzanti","doi":"10.1002/hlca.202400189","DOIUrl":"https://doi.org/10.1002/hlca.202400189","url":null,"abstract":"Despite their synthetic interest and potential attractive properties, the preparation of heteroleptic U(III) complexes containing monodentate ligands remains challenging. Here we report the synthesis, structure and magnetic properties of three heteroleptic U(III) complexes containing two siloxide donors in the coordination sphere. The bis-siloxide monoiodide complex [U(OSi(OtBu)3)2I(thf)3], 1 provides a very attractive precursor for accessing heteroleptic complexes and rationally modify the binding angle between the two strongly donating siloxide ligands. Here we reacted 1 with macrocyclic ligands to yield complexes [[U(OSi(OtBu)3)2(crypt)]I, 3 and [[U(OSi(OtBu)3)2(18c6)]I, 4. Magnetic studies of these compounds offer a snapshot on how the SMM properties depend on the local symmetry in the presence of siloxide ligands. The static and dynamic magnetic properties of these compounds reveal a weak dependence of their single-molecule magnet behavior on the local symmetry.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629773","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}

引用次数: 0

Iron-Catalyzed C–H Activation/Aza-Annulation with 2-Butyne for Accessing Methylated Aza-Arenes 铁催化C-H活化/ 2-丁炔环化氮杂芳烃的研究

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-22 DOI: 10.1002/hlca.202400200

Yan Zhang, Rui Shang, Eiichi Nakamura

{"title":"Iron-Catalyzed C–H Activation/Aza-Annulation with 2-Butyne for Accessing Methylated Aza-Arenes","authors":"Yan Zhang, Rui Shang, Eiichi Nakamura","doi":"10.1002/hlca.202400200","DOIUrl":"https://doi.org/10.1002/hlca.202400200","url":null,"abstract":"The incorporation of methyl groups into aza-arene frameworks not only often improves their biological activity as the “magic methyl” effect, but also notably affects their solid-state electronic properties by modulating π-π stackings, which makes them promising candidates for developing organic electronic materials. This study focuses on the iron-catalyzed C−H annulation of ketones with 2-butyne via their oxime ethers, offering an efficient pathway to synthesizing methylated π-extended aza-arenes. The reactions utilize isobutyl aluminum(III) catecholate as a base and Triphos (bis(2-diphenylphosphinoethyl)phenylphosphine) as a ligand. Reported C−H activation methods using rhodium catalysis proved less effective with π-conjugated substrates. Regioselective C−H aza-annulation with 1-(trimethylsilyl)propyne following desilylation provides also mono-methylated azaarenes. The reactions also generate tetra-methylated aza-arene products by two-fold C−H aza-annulation on chromeno[3,2-a]xanthene-13,14-dione and quinacridone. These methylated aza-arenes exhibit strong π-π stacking, a narrow emission band, and tunable photophysical properties, indicating their potential applications as electronic materials.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400200","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Picture: (Helv. Chim. Acta 1/2025) 封面图片：（Helv.）詹。Acta 1/2025)

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-17 DOI: 10.1002/hlca.202570101

引用次数: 0

Amoxicillin Concentrations in Samples of Musculoskeletal Infections 肌肉骨骼感染样品中的阿莫西林浓度

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-13 DOI: 10.1002/hlca.202400178

Joana Erdmann, Richard Kuehl, Mario Morgenstern, Dirk Bumann, Martin Clauss, Nina Khanna, Katharina M. Rentsch

{"title":"Amoxicillin Concentrations in Samples of Musculoskeletal Infections","authors":"Joana Erdmann, Richard Kuehl, Mario Morgenstern, Dirk Bumann, Martin Clauss, Nina Khanna, Katharina M. Rentsch","doi":"10.1002/hlca.202400178","DOIUrl":"https://doi.org/10.1002/hlca.202400178","url":null,"abstract":"Amoxicillin is a frequently used beta-lactam antibiotic and at the same time a fragile analyte. Aim of this work was to investigate the sensitive properties of amoxicillin in biological samples and validate a quantification method for amoxicillin in soft tissue samples. Simple protein precipitation and 2D-High performance liquid chromatography coupled to tandem mass spectrometry was used for sample preparation and analysis. The formation of a covalent amoxicillin methanol-adduct could be observed in varying extents depending on matrix and sample preparation method. In-Source Products (ISPs) were investigated in plasma, soft tissue, and water and no differences could be observed. We successfully validated a method for amoxicillin determination in tissue samples using the sum of 2 ISPs of amoxicillin for quantification. 37 study samples of different deep-seated infections could be analyzed. Measured amoxicillin concentrations ranged from below 0.5 mg/kg up to 87 mg/kg. Concentrations in abscesses were lower than in other infections.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Threshold Photoelectron Spectrum of 3,4-Dimethylenecyclobutene 3,4-二亚甲基环丁烯的阈值光电子谱

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-11 DOI: 10.1002/hlca.202400197

Emil Karaev, Dorothee Schaffner, Marius Gerlach, Tobias Preitschopf, Patrick Hemberger, Ingo Fischer

引用次数: 0

Effect of π-Electron Conjugation on the Chiroptical Properties of Helicene Carbon Nanohoops π-电子共轭对螺旋碳纳米环热学性能的影响

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2025-01-10 DOI: 10.1002/hlca.202400166

Kovida Kovida, Juraj Malinčík, Tomáš Šolomek

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Neutralization of an Oxytocin Derivative by 355 nm Photocleavage in High Vacuum 高真空355nm光裂解中和催产素衍生物