Solid state nuclear magnetic resonance最新文献_第8页

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

Characterization of crystalline and amorphous forms of irbesartan by multi-nuclear solid-state NMR 厄贝沙坦晶体和非晶态的多核固体核磁共振表征

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-04-01 DOI: 10.1016/j.ssnmr.2022.101783

Marcin Skotnicki , Paul Hodgkinson

{"title":"Characterization of crystalline and amorphous forms of irbesartan by multi-nuclear solid-state NMR","authors":"Marcin Skotnicki , Paul Hodgkinson","doi":"10.1016/j.ssnmr.2022.101783","DOIUrl":"10.1016/j.ssnmr.2022.101783","url":null,"abstract":"<div>Irbesartan (IRB) is an antihypertensive drug which exhibits the rare phenomenon of desmotropy; its 1H- and 2H- tetrazole tautomers can be isolated as distinct crystalline forms. The crystalline forms of IRB are poorly soluble, hence the amorphous form is potentially of interest for its faster dissolution rate. The tautomeric form and the nature of hydrogen bonding in amorphous IRB are unknown. In this study, crystalline form A and amorphous form of irbesartan were studied using 13C, 15N and 1H solid-state NMR. Variable-temperature 13C SSMNR studies showed alkyl chain disorder in the crystalline form of IRB, which may explain the conflicting literature crystal structures of form A (the marketed form). 15N NMR indicates that the amorphous material contains an approximately 2:1 ratio of 1H- and 2H-tetrazole tautomers. Static 1H SSNMR and relaxation time measurements confirmed different molecular mobilities of the samples and provided molecular-level insight into the nature of the glass transition. SSNMR is shown to be a powerful technique to investigate the solid state of disordered active pharmaceutical ingredients.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"118 ","pages":"Article 101783"},"PeriodicalIF":3.2,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49176733","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

Separating an overlapped 1H peak and identifying its 1H-1H correlations with the use of single-channel 1H solid-state NMR at fast MAS 分离重叠的1H峰，并在快速MAS下使用单通道1H固态核磁共振识别其1H-1H相关性

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-02-01 DOI: 10.1016/j.ssnmr.2022.101774

Nghia Tuan Duong , Vipin Agarwal , Yusuke Nishiyama

{"title":"Separating an overlapped 1H peak and identifying its 1H-1H correlations with the use of single-channel 1H solid-state NMR at fast MAS","authors":"Nghia Tuan Duong , Vipin Agarwal , Yusuke Nishiyama","doi":"10.1016/j.ssnmr.2022.101774","DOIUrl":"10.1016/j.ssnmr.2022.101774","url":null,"abstract":"<div>Fast magic-angle spinning (≥60 kHz) technique has enabled the acquisition of high-resolution 1H NMR spectra of solid materials. However, the spectral interpretation is still difficult because the 1H peaks are overlapped due to the narrow chemical shift range and broad linewidths. An additional 13C or 14N or 1H dimension possibly addresses the issues of overlapped proton resonances, but it leads to the elongated experimental time. Herein, we introduce a single-channel 1H experiment to separate the overlapped 1H peak and identify its spatially proximal 1H–1H correlations. This sequence combines selective excitation, selective 1H–1H polarization transfer by selective recoupling of protons (SERP), and broadband 1H recoupling by back-to-back (BABA) recoupling sequences. The concept for 1H separation is based on (i) the selective excitation of a well-resolved 1H peak and (ii) the selective dipolar polarization transfer from this isolated 1H peak to one of the 1H peaks in the overlapped/poor resolution region by SERP and (iii) the detection of 1H–1H correlations from these two 1H peaks to other neighboring 1Hs by BABA. We demonstrated the applicability of this approach to identify overlapped peaks on two molecules, β-L-aspartyl-l-alanine and Pioglitazone.HCl. The sequence allows the clear observation of 1H–1H correlations from an overlapped 1H peak without an additional heteronuclear dimension and ensures efficient polarization transfers that leads to twelve fold reduction in experimental time compared to 14N edited experiments. The limitation and the conditions of applicability for this approach are discussed in detail.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"117 ","pages":"Article 101774"},"PeriodicalIF":3.2,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39837922","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

Structural characterization of interfaces in silica core-alumina shell microspheres by solid-state NMR spectroscopy 二氧化硅核-氧化铝壳微球界面的固体核磁共振表征

IF 3.2 3区化学

Solid state nuclear magnetic resonance Pub Date : 2022-02-01 DOI: 10.1016/j.ssnmr.2022.101773

Andrea Simion , Mihai Vasilescu , Claudiu Filip , Milica Todea , Marieta Mureșan-Pop , Simion Simon

{"title":"Structural characterization of interfaces in silica core-alumina shell microspheres by solid-state NMR spectroscopy","authors":"Andrea Simion , Mihai Vasilescu , Claudiu Filip , Milica Todea , Marieta Mureșan-Pop , Simion Simon","doi":"10.1016/j.ssnmr.2022.101773","DOIUrl":"10.1016/j.ssnmr.2022.101773","url":null,"abstract":"<div>Atomic-scale description of surfaces and interfaces in core-shell aluminosilicate materials is not fully elucidated, partially due to their amorphous character and complex mechanisms that govern their properties. In this paper, new insights into nanostructured core-shell aluminosilicates have been demonstrated, by using different solid-state NMR methods, i.e 29Si, 29Si cross-polarization (CP), 27Al, 27Al triple-quantum (3Q), and 1H–27Al heteronuclear correlation (HETCOR) MAS NMR. For this purpose, nanostructured silica core-alumina shell microspheres, undoped and doped with gadolinium ions respectively, obtained by a chemical synthesis based on the Stöber method for the silica core and electrostatic attraction for developing the alumina shell were studied. As a result, a new alumino-silicate layer formation was proved at the interface between silica core, where aluminum diffuses, on small scale, in the silica network, and alumina shell, where silicon ions migrate, on a larger scale, in the alumina network, leading to a stable core-shell structure. Moreover, this process is accompanied by significant local structural changes in the transition zone, particularly at the aluminum neighborhood, which is quite well understood now, with the power of solid-state NMR spectroscopy.</div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"117 ","pages":"Article 101773"},"PeriodicalIF":3.2,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39927776","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