Magnetic Resonance in Chemistry最新文献

A New qNMR Compliant Savitzky-Golay Apodization Function for Resolution Enhancement. 用于提高分辨率的新型 qNMR 兼容型 Savitzky-Golay 光晕函数

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-03 DOI: 10.1002/mrc.5492

Carlos Cobas, José Antonio García-Pulido, Paula Mora, Giovanni Selva, Stan Sykora

引用次数: 0

NMR Relaxometry to Monitor In Situ the Loading of Amberlite IR120 and Dowex Marathon MSC Resins With Ni²⁺ and Cu²⁺ During a Column Experiment. 核磁共振弛豫测定法用于监测 Amberlite IR120 和 Dowex Marathon MSC 树脂在色谱柱实验中对 Ni2+ 和 Cu2+ 的原位加载。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-30 DOI: 10.1002/mrc.5490

Marie Bernardi, Rodrigo de Oliveira Silva, Quoc Lam Vuong, Dimitrios Sakellariou, Yves Gossuin

{"title":"NMR Relaxometry to Monitor In Situ the Loading of Amberlite IR120 and Dowex Marathon MSC Resins With Ni2+ and Cu2+ During a Column Experiment.","authors":"Marie Bernardi, Rodrigo de Oliveira Silva, Quoc Lam Vuong, Dimitrios Sakellariou, Yves Gossuin","doi":"10.1002/mrc.5490","DOIUrl":"https://doi.org/10.1002/mrc.5490","url":null,"abstract":"The removal of heavy metal ions from wastewater often necessitates the use of ion exchange resins. Current methods for assessing ion exchange efficiency are indirect and destructive. Some heavy metal ions, such as Cu2+ and Ni2+, are paramagnetic and influence the NMR relaxation times of water protons. NMR relaxometry can therefore be utilized to track the removal of these ions by ion exchange resins. In this study, we use relaxometry to monitor in situ the loading with Ni2+ and Cu2+ of Amberlite IR120 and Dowex Marathon MSC resins, with the resin column inserted into a low-field NMR device. The multiexponential transverse relaxation curves were fitted using a biexponential model. Before and during the loading of the resin, the water with the slowest relaxation corresponds to treated water (free of Ni2+ or Cu2+) flowing between the resin beads. After saturation, the slowest fraction corresponds to the untreated solution (containing Ni2+ or Cu2+) flowing between the resin beads saturated with paramagnetic ions. The evolution with time of the transverse relaxation rate and the amplitude of the slowly relaxing water fraction shows a clear transition, occurring later at the bottom of the resin bed compared with the middle and top. This is interpreted as an indication of the saturation of the studied zone with paramagnetic ions, confirmed by the quantification of Ni2+ or Cu2+ in the effluent using AES spectroscopy. This proof-of-concept study demonstrates that NMR relaxometry can be used in situ to monitor the loading of a resin bed with paramagnetic ions.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546278","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}

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To Gibbs or Not to Gibbs Effect of Entropic Contribution in the NMR Calculations of Flexible and Polar Molecules-Updating the DP4+App. 柔性和极性分子核磁共振计算中熵贡献的吉布斯效应（To Gibbs or Not to Gibbs Effect of Entropic Contribution in the NMR Calculations of Flexible and Polar Molecules）-更新 DP4+App.

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-30 DOI: 10.1002/mrc.5491

Milagros Amichetti, Bruno A Franco, María Marta Zanardi, Ariel M Sarotti

引用次数: 0

Deciphering the Conformations of Glutathione Oxidized Peptide: A Comparative NMR Study in Solution and Solid-State Environments. 解密谷胱甘肽氧化肽的构象：溶液和固态环境下的核磁共振对比研究。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-16 DOI: 10.1002/mrc.5486

Dillip K Senapati, Jayasubba Reddy Yarava, K V Ramanathan, S Raghothama

{"title":"Deciphering the Conformations of Glutathione Oxidized Peptide: A Comparative NMR Study in Solution and Solid-State Environments.","authors":"Dillip K Senapati, Jayasubba Reddy Yarava, K V Ramanathan, S Raghothama","doi":"10.1002/mrc.5486","DOIUrl":"https://doi.org/10.1002/mrc.5486","url":null,"abstract":"Glutathione (GSH) and its oxidized dimer (GSSG) play an important role in living systems as an antioxidant, balancing the presence of reactive oxygen species (ROS). The central thiol (-S-S-) bond in GSSG can undergo free rotation, providing multiple conformations with respect to the S-S bridge. The six titratable sites of GSSG, which are influenced by pH variations, affect these conformations in solution, whereas in solids, additionally crystal packing effects come into play. In view of differing reports about the structure of GSSG in literature, we have here conducted an extensive reexamination of its conformations using NMR, and contrasting results have been obtained for solution and solid state. In solution, the existence of more than one antiparallel orientation of the monomer unit with different hydrogen bonding schemes has been indicated by NOE and amide temperature coefficient results. On the other hand, in the solid-state, a 1H-1H double-quantum (DQ) to 13C single-quantum (SQ) correlation study has confirmed a parallel orientation, consistent with the reported X-ray crystal structure. Experimentally assigned solid-state NMR resonances have been validated using GIPAW calculations incorporated in the Quantum ESPRESSO package.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469117","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}

引用次数: 0

Understanding the Interactions of Nanoparticles and Dissolved Organic Matter at the Molecular Level by ¹H 2D Multi-Exponential Transverse Relaxation NMR Spectroscopy. 通过 1H 2D 多指数横向弛豫 NMR 光谱了解纳米粒子与溶解有机物在分子水平上的相互作用。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-16 DOI: 10.1002/mrc.5487

Malak Dia, Jonathan Farjon, Clotilde Raveleau, André Simpson, Pierre-Emmanuel Peyneau, Béatrice Béchet, Denis Courtier-Murias

{"title":"Understanding the Interactions of Nanoparticles and Dissolved Organic Matter at the Molecular Level by 1H 2D Multi-Exponential Transverse Relaxation NMR Spectroscopy.","authors":"Malak Dia, Jonathan Farjon, Clotilde Raveleau, André Simpson, Pierre-Emmanuel Peyneau, Béatrice Béchet, Denis Courtier-Murias","doi":"10.1002/mrc.5487","DOIUrl":"https://doi.org/10.1002/mrc.5487","url":null,"abstract":"The interaction between humic acid (HA) and engineered nanoparticles (NPs) is critical in environmental sciences, especially for understanding the behavior of NPs in natural waters. This study employs 1H 2D Multi-Exponential Transverse Relaxation (METR) NMR spectroscopy to examine the molecular-level interactions between Pahokee Peat humic acid (HA) and carboxyl-functionalized iron oxide nanoparticles (NPCOs). First, 1H 2D METR NMR spectroscopy allowed not only the identification of HA in terms of its chemical composition but also the separation of molecules with the same chemical shift values but different rates of molecular tumbling. Then, using solutions with varying NPCO concentrations (0, 10, 40, and 100 μM), we observed significant changes in the T2 relaxation times of HA components, indicating interactions between HA and NPCO. Analysis showed the biggest effect on two chemical shift regions, corresponding to lipids and carbohydrates, revealing that smaller molecules within these regions exhibit the most significant changes in T2 values upon the addition of NPCO. This suggests that these molecules are the initial sites of interaction, with the entire HA system being affected at higher NPCO concentrations. These findings highlight the utility of METR NMR spectroscopy in studying complex environmental mixtures and provide insights into the behavior of HA and NPs, essential for understanding the fate of NPs in the environment.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469121","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}

引用次数: 0

Determination of the pK_a Value of a Brønsted Acid by ¹⁹F NMR Spectroscopy. 通过 19F NMR 光谱测定布氏酸的 pKa 值。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-16 DOI: 10.1002/mrc.5485

Emily F Griffiths, Jay A Dixon, Andrew J M Caffyn, Stuart K Langley, Beatriz Maciá, Vittorio Caprio, Ryan E Mewis

{"title":"Determination of the pKa Value of a Brønsted Acid by 19F NMR Spectroscopy.","authors":"Emily F Griffiths, Jay A Dixon, Andrew J M Caffyn, Stuart K Langley, Beatriz Maciá, Vittorio Caprio, Ryan E Mewis","doi":"10.1002/mrc.5485","DOIUrl":"https://doi.org/10.1002/mrc.5485","url":null,"abstract":"Brønsted acids, such as phosphoric acids derived from chiral 1,1'-bi-2-naphthol (BINOL), are important catalysts in the formation of carbon-carbon and carbon-heteroatom bonds, for example. The catalytic activity of these Brønsted acids is strongly linked to their acidity, and as such, the evaluation of compounds to determine pKa values provides insight into their catalytic activity. Herein, a 19F{1H} NMR methodology is detailed to determine the pKa of a fluorinated binaphthyl-derived phosphinic acid, rac-1, in acetonitrile and in the presence of a fluorinated sulfonamide reference compound (2-4). The approach was tested initially using 2 and 3, with the ΔpKa (0.08) in strong agreement with previously reported values (6.6 for 2 and 6.68/6.73 for 3). Sigmoidal curves of normalised chemical shift change (Δδ) against equivalents of the base phosphazene P1-tBu added overlapped for 2 and 3, but in the case of rac-1 and either 2, 3 or 4, there was significant separation. A variety of different approaches for determining the ΔpKa were compared. Values of pKa determined when the normalised Δδ was 90% were optimal for 2 and 3, whereas a normalised Δδ of 75% was optimal for 4, resulting in the pKa of rac-1 being determined to be 8.47-8.71.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469118","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}

引用次数: 0

NMR Coupling Constants, Karplus Equations, and Adjusted MD Statistics: Detecting Diagnostic Torsion Angles for the Solution Geometry of 6-[α-d-Mannopyranosyl]-d-Mannopyranose (Mannobiose). NMR 耦合常数、Karplus 方程和调整 MD 统计量：检测 6-[α-d-吡喃甘露糖基]-d-吡喃甘露糖（甘露糖）溶液几何的诊断性扭转角。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-16 DOI: 10.1002/mrc.5483

Andreas H Franz, Kendall S Bromley, Ei T Aung, Stephen Q L Do, Hana M Rosenblatt, Amelia J Watson

引用次数: 0

Speedy Component Resolution Using Spatially Encoded Diffusion NMR Data. 利用空间编码扩散核磁共振数据快速分辨成分

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-16 DOI: 10.1002/mrc.5488

Benjamin Lorandel, Hugo Rocha, Oksana Cazimajou, Rituraj Mishra, Aurélie Bernard, Paul Bowyer, Mathias Nilsson, Jean-Nicolas Dumez

{"title":"Speedy Component Resolution Using Spatially Encoded Diffusion NMR Data.","authors":"Benjamin Lorandel, Hugo Rocha, Oksana Cazimajou, Rituraj Mishra, Aurélie Bernard, Paul Bowyer, Mathias Nilsson, Jean-Nicolas Dumez","doi":"10.1002/mrc.5488","DOIUrl":"https://doi.org/10.1002/mrc.5488","url":null,"abstract":"Diffusion-ordered NMR spectroscopy (DOSY) is a powerful tool to analyse mixtures. Spatially encoded (SPEN) DOSY enables recording a full DOSY dataset in just one scan by performing spatial parallelisation of the gradient dimension. The simplest and most widely used approach to processing DOSY data is to fit each peak in the spectrum with a single or multiple exponential decay. However, when there is peak overlap, and/or when the diffusion decays of the contributing components are too similar, this method has limitations. Multivariate analysis of DOSY data, which is an attractive alternative, consists of decomposing the experimental data, into compound-specific diffusion decays and 1D NMR spectra. Multivariate analysis has been very successfully used for conventional DOSY data, but its use for SPEN DOSY data has only recently been reported. Here, we present a comparison, for SPEN DOSY data, of two widely used algorithms, SCORE and OUTSCORE, that aim at unmixing the spectra of overlapped species through a least square fit or a cross-talk minimisation, respectively. Data processing was performed with the General NMR Analysis Toolbox (GNAT), with custom-written code elements that now expands the capabilities, and makes it possible to import and process SPEN DOSY data. This comparison is demonstrated on three different two-component mixtures, each with different characteristics in terms of signal overlap, diffusion coefficient similarity, and component concentration.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142469120","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}

引用次数: 0

Simple and Effective Identification of Local 6π- and Global [4n + 2] Aromaticity of Macrocyclic Conjugated Hydrocarbons by 1H/13C Chemical Shifts and the Corresponding Ring Current Effect 通过 1H/13C 化学位移和相应的环流效应，简单有效地识别大环共轭烃的局部 6π- 和全局 [4n + 2] 芳香性。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-08 DOI: 10.1002/mrc.5482

Erich Kleinpeter, Andreas Koch

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Effect of Solvent on the Optical Rotation of Azatryptophan Derivatives 溶剂对氮杂色氨酸衍生物光学旋转的影响。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-09-24 DOI: 10.1002/mrc.5481

Mitalee Das, Felix Kulandai, Hemantha Kumar, Prakasam Kuppuswamy, Bandreddy Subba, Sunit Hazra, Roshan Nimje, Anuradha Gupta, Muralidhararao Bagadi, Arvind Mathur, Amrita Roy, Sharad Duche

{"title":"Effect of Solvent on the Optical Rotation of Azatryptophan Derivatives","authors":"Mitalee Das, Felix Kulandai, Hemantha Kumar, Prakasam Kuppuswamy, Bandreddy Subba, Sunit Hazra, Roshan Nimje, Anuradha Gupta, Muralidhararao Bagadi, Arvind Mathur, Amrita Roy, Sharad Duche","doi":"10.1002/mrc.5481","DOIUrl":"10.1002/mrc.5481","url":null,"abstract":"<div>\u0000 \u0000 Chirally pure enantiomers of differently protected 7-azatryptophan derivatives (R-3c, S-3c, R-3i, S-3i, R-3m, S-3m, R-3aa, and S-3aa) were synthesized, which showed solvent-dependent optical rotation. The obtained results not only exhibited changes in the values but also showed the variation in sign (− or +) with the different solvents studied. The change in optical rotation value was essentially attributed to the electron-donating property, which can be correlated to the donor number of the solvents. There are two types of hydrogen bonds, intramolecular (i.e., form within the structure) and intermolecular (i.e., form with external groups such as solvents). These hydrogen bonds are responsible for the value and sign variations, and 1H NMR experiments were used to further characterize them. The NMR data suggested that hydrogen bond formation is occurring between the Fmoc NH group vicinal to the chiral center and donor group of the corresponding solvent.\u0000 </div>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142308073","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}

引用次数: 0