Solid state nuclear magnetic resonance最新文献_第7页

19F Solid-state NMR characterization of pharmaceutical solids 19F药物固体的固体核磁共振表征

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-08-01 DOI: 10.1016/j.ssnmr.2022.101796

Yong Du , Yongchao Su

引用次数: 7

t1-noise elimination by continuous chemical shift anisotropy refocusing t1-连续化学位移各向异性重聚焦噪声消除

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-08-01 DOI: 10.1016/j.ssnmr.2022.101807

Frédéric A. Perras , Tian Wei Goh , Wenyu Huang

引用次数: 3

High resolution solid state NMR in paramagnetic metal-organic frameworks 顺磁性金属-有机骨架的高分辨率固态核磁共振

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-08-01 DOI: 10.1016/j.ssnmr.2022.101811

C.A. Klug , M.W. Swift , J.B. Miller , J.L. Lyons , A. Albert , M. Laskoski , C.M. Hangarter

{"title":"High resolution solid state NMR in paramagnetic metal-organic frameworks","authors":"C.A. Klug , M.W. Swift , J.B. Miller , J.L. Lyons , A. Albert , M. Laskoski , C.M. Hangarter","doi":"10.1016/j.ssnmr.2022.101811","DOIUrl":"10.1016/j.ssnmr.2022.101811","url":null,"abstract":"<div>We study the metal-organic framework (MOF) ZIF-67 with 1H and 13C nuclear magnetic resonance (NMR). In addition to the usual orbital chemical shifts, we observe spinning sideband manifolds in the NMR spectrum due to hyperfine interactions of the paramagnetic cobalt with 1H and 13C. Both orbital and paramagnetic chemical shifts are in good agreement with values calculated from first principles, allowing high-confidence assignment of the observed peaks to specific sites within the MOF. Our measured resonance shifts, line shapes, and spin lattice relaxation rates are also consistent with calculated values. We show that molecules in the pores of the MOF can exhibit high-resolution NMR spectra with fast spin lattice relaxation rates due to dipole-dipole couplings to the Co2+ nodes in the ZIF-67 lattice, showcasing NMR spectroscopy as a powerful tool for identification and characterization of “guests” that may be hosted by the MOF in electrochemical and catalytic applications.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101811"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0926204022000406/pdfft?md5=c4eb532d7f6257a0c6aa6ce21befe8f8&pid=1-s2.0-S0926204022000406-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40484908","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}

引用次数: 1

Probing adsorption of water and DMF in UiO-66(Zr) using solid-state NMR 固体核磁共振探测UiO-66(Zr)对水和DMF的吸附

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-08-01 DOI: 10.1016/j.ssnmr.2022.101797

Florian Venel, Christophe Volkringer, Olivier Lafon, Frédérique Pourpoint

引用次数: 1

Long single pulse NQR for broad resonance lines 宽共振线的长单脉冲NQR

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-08-01 DOI: 10.1016/j.ssnmr.2022.101810

T.C.L. Ly, R. Yong, D.G. Miljak

引用次数: 0

Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids γ辐照有机分子固体的魔角自旋动态核极化固体核磁共振谱

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-06-01 DOI: 10.1016/j.ssnmr.2022.101785

Scott L. Carnahan , Yunhua Chen , James F. Wishart , Joseph W. Lubach , Aaron J. Rossini

{"title":"Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids","authors":"Scott L. Carnahan , Yunhua Chen , James F. Wishart , Joseph W. Lubach , Aaron J. Rossini","doi":"10.1016/j.ssnmr.2022.101785","DOIUrl":"10.1016/j.ssnmr.2022.101785","url":null,"abstract":"<div>In the past 15 years, magic angle spinning (MAS) dynamic nuclear polarization (DNP) has emerged as a method to increase the sensitivity of high-resolution solid-state NMR spectroscopy experiments. Recently, γ-irradiation has been used to generate significant concentrations of homogeneously distributed free radicals in a variety of solids, including quartz, glucose, and cellulose. Both γ-irradiated quartz and glucose previously showed significant MAS DNP enhancements. Here, γ-irradiation is applied to twelve small organic molecules to test the applicability of γ-irradiation as a general method of creating stable free radicals for MAS DNP experiments on organic solids and pharmaceuticals. Radical concentrations in the range of 0.25 mM–10 mM were observed in irradiated glucose, histidine, malic acid, and malonic acid, and significant 1H DNP enhancements of 32, 130, 19, and 11 were obtained, respectively, as measured by 1H→13C CPMAS experiments. However, concentrations of free radicals below 0.05 mM were generally observed in organic molecules containing aromatic rings, preventing sizeable DNP enhancements. DNP sensitivity gains for several of the irradiated compounds exceed that which can be obtained with the relayed DNP approach that uses exogeneous polarizing agent solutions and impregnation procedures. In several cases, significant 1H DNP enhancements were realized at room temperature. This study demonstrates that in many cases γ-irradiation is a viable alternative to addition of stable exogenous radicals for DNP experiments on organic solids.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"119 ","pages":"Article 101785"},"PeriodicalIF":3.2,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45272824","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: 5

Multinuclear solid-state NMR: Unveiling the local structure of defective MOF MIL-120 多核固体核磁共振:揭示缺陷MIL-120的局部结构

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-06-01 DOI: 10.1016/j.ssnmr.2022.101793

Wanli Zhang , Shoushun Chen , Victor V. Terskikh , Bryan E.G. Lucier , Yining Huang

{"title":"Multinuclear solid-state NMR: Unveiling the local structure of defective MOF MIL-120","authors":"Wanli Zhang , Shoushun Chen , Victor V. Terskikh , Bryan E.G. Lucier , Yining Huang","doi":"10.1016/j.ssnmr.2022.101793","DOIUrl":"10.1016/j.ssnmr.2022.101793","url":null,"abstract":"<div>Metal-organic frameworks (MOFs) are emerging materials with many current and potential applications due to their unique properties. One critical feature is that the physical and chemical properties of MOFs are tunable. One of the methods for tuning MOF properties is to introduce defects by design for desired applications. Characterization of MOF defects is important, but very challenging due to the local nature and short-range ordering. In this work, we have introduced the ordered vacancies (the defects) in the form of the coordinatively unsaturated sites (CUSs) into the framework of MOF MIL-120(Al). The creation of ordered vacancies is achieved by replacing one quarter of the BTEC (1,2,4,5-benzenetetracarboxylate) with BDC (benzene-1,4-dicarboxylate) linkers. Both parent and defective MOFs were characterized by multinuclear solid-state NMR spectroscopy. 1H MAS NMR is used to characterize the hydrogen bonding in these MOFs, whereas 13C CP MAS NMR confirms unambiguously that the BDC is incorporated into the framework. One-dimensional 27Al MAS NMR provides direct evidence of the coordinatively unsaturated Al sites (the defects). Furthermore, 27Al 3QMAS experiments at 21.1 T allow direct identification of one penta-coordinated and three chemically inequivalent octahedral Al sites in the defective MIL-120(Al). Two of the above-mentioned octahedral Al sites are in the domain which appears defect-free. The third octahedral Al site is near the defective site. This work clearly demonstrates the power of solid-state NMR spectroscopy for characterization of defective MOFs.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"119 ","pages":"Article 101793"},"PeriodicalIF":3.2,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46298934","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: 1

Complete resonance assignment of a pharmaceutical drug at natural isotopic abundance from DNP-Enhanced solid-state NMR 从dnp增强的固态核磁共振中获得天然同位素丰度的药物的完整共振分配

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-06-01 DOI: 10.1016/j.ssnmr.2022.101794

Renny Mathew , Ivan V. Sergeyev , Fabien Aussenac , Lydia Gkoura , Melanie Rosay , Maria Baias

{"title":"Complete resonance assignment of a pharmaceutical drug at natural isotopic abundance from DNP-Enhanced solid-state NMR","authors":"Renny Mathew , Ivan V. Sergeyev , Fabien Aussenac , Lydia Gkoura , Melanie Rosay , Maria Baias","doi":"10.1016/j.ssnmr.2022.101794","DOIUrl":"10.1016/j.ssnmr.2022.101794","url":null,"abstract":"<div>Solid-state dynamic nuclear polarization enhanced magic angle spinning (DNP-MAS) NMR measurements coupled with density functional theory (DFT) calculations enable the full resonance assignment of a complex pharmaceutical drug molecule without the need for isotopic enrichment. DNP dramatically enhances the NMR signals, thereby making possible previously intractable two-dimensional correlation NMR spectra at natural abundance. Using inputs from DFT calculations, herein we describe a significant improvement to the structure elucidation process for complex organic molecules. Further, we demonstrate that a series of two-dimensional correlation experiments, including 15N–13C TEDOR, 13C–13C INADEQUATE/SARCOSY, 19F–13C HETCOR, and 1H–13C HETCOR, can be obtained at natural isotopic abundance within reasonable experiment times, thus enabling a complete resonance assignment of sitagliptin, a pharmaceutical used for the treatment of type 2 diabetes.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"119 ","pages":"Article 101794"},"PeriodicalIF":3.2,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0926204022000236/pdfft?md5=37edeb9b3fa6812c2fb544dd1320984c&pid=1-s2.0-S0926204022000236-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46931050","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}

引用次数: 0

To what extent do bond length and angle govern the 13C and 1H NMR response to weak CH⋯O hydrogen bonds? A case study of caffeine and theophylline cocrystals 键长和键角在多大程度上控制13C和1H核磁共振对弱CH⋯O氢键的响应?咖啡因和茶碱共晶的个案研究

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-06-01 DOI: 10.1016/j.ssnmr.2022.101795

Scott A. Southern , David L. Bryce

{"title":"To what extent do bond length and angle govern the 13C and 1H NMR response to weak CH⋯O hydrogen bonds? A case study of caffeine and theophylline cocrystals","authors":"Scott A. Southern , David L. Bryce","doi":"10.1016/j.ssnmr.2022.101795","DOIUrl":"10.1016/j.ssnmr.2022.101795","url":null,"abstract":"<div>Weak hydrogen bonds are important structure-directing elements in supramolecular chemistry and biochemistry. We consider here weak CH⋯O hydrogen bonds in a series of cocrystals of theophylline and caffeine and assess to what extent the CH⋯O distance and angle govern the observed 13C and 1H isotropic chemical shifts. Gauge-including projector-augmented wave density functional theory (GIPAW DFT) calculations consistently predict a decrease in the 13C and 1H magnetic shielding constants upon hydrogen bond formation on the order of 2–5 ppm (13C) and 1–2 ppm (1H). These trends are reproduced using the machine-learning approach implemented in ShiftML. Experimental 13C and 1H chemical shifts obtained for powdered samples using one-dimensional NMR spectroscopy as well as heteronuclear correlation (HETCOR) spectroscopy correlate well with the GIPAW DFT results. However, the experimental 13C NMR response only correlates moderately well with the hydrogen bond length and angle, while the experimental 1H chemical shifts only show very weak correlations to these local structural elements. DFT computations on isolated imidazole-formaldehyde models show that the 13C and 1H chemical shifts generally decrease with the C⋯O distance but show no clear dependence on the CH⋯O angle. These results demonstrate that the 13C and 1H response to weak CH⋯O hydrogen bonding is influenced significantly by additional weak contacts within cocrystal heterodimeric units.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"119 ","pages":"Article 101795"},"PeriodicalIF":3.2,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48434460","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: 2

Butane isomers mobility and framework dynamics in UiO-66 (Zr) MOF: Impact of the hydroxyl groups in zirconia cluster UiO-66 (Zr) MOF中丁烷异构体的迁移率和骨架动力学:氧化锆簇中羟基的影响

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-04-01 DOI: 10.1016/j.ssnmr.2022.101784

Alexander E. Khudozhitkov , Sergei S. Arzumanov , Daniil I. Kolokolov , Alexander G. Stepanov

{"title":"Butane isomers mobility and framework dynamics in UiO-66 (Zr) MOF: Impact of the hydroxyl groups in zirconia cluster","authors":"Alexander E. Khudozhitkov , Sergei S. Arzumanov , Daniil I. Kolokolov , Alexander G. Stepanov","doi":"10.1016/j.ssnmr.2022.101784","DOIUrl":"10.1016/j.ssnmr.2022.101784","url":null,"abstract":"<div>UiO-66 (Zr) is a metal-organic framework (MOF) known for its thermal and chemical stability and wide range of adsorption-based applications. This MOF exhibits high separation selectivity for butane isomers. It has been earlier inferred that the separation performance of the material depends on the hydroxylation state of the zirconia cluster. In this contribution, we apply 2H solid-state NMR to characterize the dynamics of both the MOF organic framework itself and butane isomers in hydroxylated and dehydroxylated forms of UiO-66. It is established that the rate of π-flipping and the amplitude of the phenylene ring plane librations in the framework are higher for the dehydroxylated form. Self-diffusion coefficients of butane isomers have been estimated for both forms of UiO-66. The diffusivity is higher for n-butane in the dehydroxylated form, whereas the diffusion of isobutane is not affected by the presence of OH groups in the zirconia cluster of the MOF. Higher diffusivity of n-butane in dehydroxylated form is accounted for by the larger effective diameter of the window between the adjacent cages in this form, which arises from faster rotation and larger amplitude of framework linker libration. This rationalizes the higher efficiency of the dehydroxylated form of UiO-66(Zr) material for butane isomers separation.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"118 ","pages":"Article 101784"},"PeriodicalIF":3.2,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45870397","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: 2