Helvetica Chimica Acta最新文献

Cover Picture: (Helv. Chim. Acta 11/2024) 封面图片：（Helv.）

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-11-16 DOI: 10.1002/hlca.202471101

引用次数: 0

The pKa of Water and the Fundamental Laws Describing Solution Equilibria: An Appeal for a Consistent Thermodynamic Pedagogy 水的 pKa 和描述溶液平衡的基本规律：呼吁采用一致的热力学教学法

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-11-13 DOI: 10.1002/hlca.202400103

Thomas L. Neils, Stephanie Schaertel, Todd P. Silverstein

{"title":"The pKa of Water and the Fundamental Laws Describing Solution Equilibria: An Appeal for a Consistent Thermodynamic Pedagogy","authors":"Thomas L. Neils, Stephanie Schaertel, Todd P. Silverstein","doi":"10.1002/hlca.202400103","DOIUrl":"https://doi.org/10.1002/hlca.202400103","url":null,"abstract":"A recurring misconception in some textbooks and research papers has led to an abandonment of fundamental physical laws when describing a subset of acid-base equilibria, especially regarding the role of the solvent. In the specific case of the autoprotolysis of water, experiments and theoretical calculations prove that the Kw of water at 25 °C, 1.00×10−14, is identical to its acid ionization constant, Ka. Nevertheless, several articles have been published erroneously purporting to give theoretical proof that the Ka of water is 10−15.743 (1.81×10−16) and that the Ka of the aqueous proton (hydronium ion) is 55.3 rather than 1.00. Here we argue that using the incorrect numbers has pedagogical implications beyond those of a simple error. Arguments for the incorrect Ka and pKa values require a misapplication of Henry's law and violate long-standing methods that use Raoult's law and the conservation of matter to describe the behavior of solutions. As a result, chemistry students may be asked to accept one set of physical principles in one course and another set in another course. Here we argue for adherence to fundamental physical laws governing solution equilibria as applied to the autoprotolysis of water and all aqueous acid base equilibria.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 11","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664954","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

Total Synthesis of Tagitinins, Goyazensolide and Related Furanoheliangolides and their Covalent Interaction with Importin-5 (IPO5) Tagitinins 、Goyazensolide 和相关呋喃香葱内酯的全合成及其与导入素-5 (IPO5) 的共价相互作用

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-27 DOI: 10.1002/hlca.202400122

Weilong Liu, Rémi Patouret, Elsa Peev, Sofia Barluenga, Nicolas Winssinger

{"title":"Total Synthesis of Tagitinins, Goyazensolide and Related Furanoheliangolides and their Covalent Interaction with Importin-5 (IPO5)","authors":"Weilong Liu, Rémi Patouret, Elsa Peev, Sofia Barluenga, Nicolas Winssinger","doi":"10.1002/hlca.202400122","DOIUrl":"https://doi.org/10.1002/hlca.202400122","url":null,"abstract":"Herein, we detail an extension of our research on the synthesis of a small library of furanoheliangolides and the characterization of the covalent interaction between goyazensolide and IPO5. Using a build-couple-pair strategy, we assembled a small library of germacrene-type lactones and diversified them into eight groups of structurally different analogues. The germacrene lactones were synthesized using Sonogashira coupling and Barbier-type macrocyclization, while the furanoheliangolides were further elaborated through gold-catalyzed transannulation followed by esterification. This synthetic approach enabled the generation of a goyazensolide alkyne-tagged cellular probe, which was used to identify the selective binding between goyazensolide and the oncoprotein importin-5 (IPO5). Mass spectrometry analysis of the proteolytic digest from the reaction between the goyazensolide probe and a recombinant IPO5 indicated a covalent engagement at Cys560 of IPO5, which was confirmed by site-directed mutagenesis.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 11","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665114","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

Electronic Structures of Late versus Early Transition Metal Imido Complexes from 15N-NMR Signatures 从 15N-NMR 信号看晚期过渡金属亚胺配合物与早期过渡金属亚胺配合物的电子结构

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-27 DOI: 10.1002/hlca.202400142

Yuya Kakiuchi, Christophe Copéret

{"title":"Electronic Structures of Late versus Early Transition Metal Imido Complexes from 15N-NMR Signatures","authors":"Yuya Kakiuchi, Christophe Copéret","doi":"10.1002/hlca.202400142","DOIUrl":"https://doi.org/10.1002/hlca.202400142","url":null,"abstract":"Imido ligand is a ubiquitous motif in organometallic chemistry, serving roles spanning from ancillary ligands to reactive sites. The nature of M=N bond is highly depended on the metal centres and their d-electron configuration, with late transition metal (TM) imido complexes exhibiting contrasting features when compared to their early TM analogues. Envisioning to uncover general electronic descriptor for the nature of imido ligands, we computationally investigate the solid-state 15N NMR signatures of late TM imido complexes with various central metals, geometries and d-electron counts, and compare them against these of the corresponding early TM systems. The spectroscopic signatures are mostly driven by the presence of filled, π-symmetry orbitals in late TM imido complexes, suggesting the development of high-lying π(M=N) and low-lying σ/σ*(M=N) orbitals. This contrasts with what is observed for the reported early TM systems, for which high-lying σ-type orbitals determine the NMR signature. Noteworthily, Ni- and Pd-imido complexes with formal d10 configurations exhibit highly asymmetric nitrogen-15 NMR signature with extremely deshielded principal components, because of the presence of filled, high-lying antibonding π*(M=N) orbitals, consistent with their high reactivity. The sensitive response of 15N NMR signature to the nature of metal sites further highlights that chemical shift is a useful reactivity descriptor.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 11","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400142","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665113","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 10/2024) 封面图片：（Helv.）

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-25 DOI: 10.1002/hlca.202471001

引用次数: 0

A Chiral Propeller-Shaped Triple Helicene Shows Multi-Resonant Thermally Activated Delayed Fluorescence 手性螺旋桨形三螺旋烯显示多谐振热激活延迟荧光

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-14 DOI: 10.1002/hlca.202400129

Jingxiang Wang, Jhon Sebastian Oviedo Ortiz, Aidan P. McKay, David B. Cordes, Jeanne Crassous, Eli Zysman-Colman

{"title":"A Chiral Propeller-Shaped Triple Helicene Shows Multi-Resonant Thermally Activated Delayed Fluorescence","authors":"Jingxiang Wang, Jhon Sebastian Oviedo Ortiz, Aidan P. McKay, David B. Cordes, Jeanne Crassous, Eli Zysman-Colman","doi":"10.1002/hlca.202400129","DOIUrl":"https://doi.org/10.1002/hlca.202400129","url":null,"abstract":"Multi-resonant thermally activated delayed fluorescence (MR-TADF) helicenes show great potential as chiral emitters due to their typically high photoluminescence quantum yield and that they emit circularly polarized luminescence. Here, a new propeller-shaped chiral MR-TADF helicene DiKTa3, integrating three DiKTa moieties, was designed and synthesized aiming to achieve co-parallel electronic and magnitude transition dipole moments that would lead to a high dissymmetry factor, g. It emits at λPL of 491 nm, with a full width at half maximum of 52 nm and has a moderate ΔEST value of 0.24 eV in toluene. The separated (P,P,P) enantiomer shows an absorption dissymmetry factor |gabs| of 6.8×10−4 at 450 nm, which results from a lower symmetry conformation adopted by the compound in solution than the C3-symmetric optimized structure. This work highlights the strong influence that geometry can have on the chiroptical properties of the emitter.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 11","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400129","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664967","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

Facile Synthesis of Phthalazinone/Isoindolinone Substituted Fluorescence Active Indolo[1,2-a]quinoxaline Derivatives via ANRORC and Fluorescence Turn Off Sensing of Fe2+ 通过 ANRORC 和 Fe2+ 的荧光关闭传感轻松合成酞嗪酮/异吲哚啉酮取代的具有荧光活性的吲哚并[1,2-a]喹喔啉衍生物

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-10 DOI: 10.1002/hlca.202400069

Arun Dhurey, Dr. Saheli Sarkar, Prof. Dr. Animesh Pramanik

{"title":"Facile Synthesis of Phthalazinone/Isoindolinone Substituted Fluorescence Active Indolo[1,2-a]quinoxaline Derivatives via ANRORC and Fluorescence Turn Off Sensing of Fe2+","authors":"Arun Dhurey, Dr. Saheli Sarkar, Prof. Dr. Animesh Pramanik","doi":"10.1002/hlca.202400069","DOIUrl":"https://doi.org/10.1002/hlca.202400069","url":null,"abstract":"Synthesis of a series of indolo[1,2-a]quinoxaline derivatives substituted with phthalazinones/isoindolinones/carbonyl benzoylesters at C-4 position have been accomplished under open air rt/heating conditions following ANRORC (Addition of Nucleophile, Ring Opening and Ring Closure) mechanism. Initially condensation of 2-(1-indolyl)-aniline and ninhydrin generates a spirocyclic intermediate 5′H-spiro[indene-2,6′-indolo[1,2-a]quinoxaline]-1,3-dione, which upon reaction with various nucleophiles like hydrazine/phenylhydrazine, amines and alcohols affords C-4 substituted indolo[1,2-a]quinoxalines in high yield (up to ~88 %) via ANRORC. The photophysical investigation shows that the quinoxaline derivatives possess significant fluorescence property with high quantum yield (QY~11.0–17.0). The N-phenylphthalazinone substituted indolo[1,2-a]quinoxaline, a molecule structurally similar to 2,2′-bipyridine system, can efficiently and selectively detect Fe2+ through fluorescence turn off sensing.","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 11","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664848","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

Selective Carbohydrate Deacetylation: Simple and Mild Approach based on Supported Copper Nanoparticles 选择性碳水化合物脱乙酰化：基于纳米铜支撑颗粒的简单温和方法

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-10-04 DOI: 10.1002/hlca.202400120

Joaquín Marchán-García, Marcos J. Lo Fiego, Yanina Moglie

引用次数: 0

Sascha Hoogendoorn Sascha Hoogendoorn

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-09-27 DOI: 10.1002/hlca.202400123

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Divergent Synthesis of Trifluoromethyl Ketones via Photoredox Activation of Halotrifluoroacetones 通过光氧化活化卤代三氟丙酮分歧合成三氟甲基酮

IF 1.5 4区化学

Helvetica Chimica Acta Pub Date : 2024-09-25 DOI: 10.1002/hlca.202400125

Rahul Giri, Mathias Kissling, Egor Zhilin, Anthony J. Fernandes, Quentin E. L. Ordan, Dmitry Katayev

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