Solid state nuclear magnetic resonance最新文献

{"title":"Solid-state NMR studies of metal ion and solvent influences upon the flexible metal-organic framework DUT-8","authors":"Marcus Rauche ,&nbsp;Sebastian Ehrling ,&nbsp;Leila Abylgazina ,&nbsp;Christopher Bachetzky ,&nbsp;Irena Senkovska ,&nbsp;Stefan Kaskel ,&nbsp;Eike Brunner","doi":"10.1016/j.ssnmr.2022.101809","DOIUrl":"10.1016/j.ssnmr.2022.101809","url":null,"abstract":"<div><p><span>Within the present contribution, we describe solid-state NMR spectroscopic studies of the paddle wheel unit in the prototypic flexible MOF compound DUT-8(M) (M = Ni, Co, Zn). The </span>¹³<span>C NMR chemical shift of these carboxylates shows a remarkable behavior. The pure 2,6-H</span>₂ndc linker carboxylates as well as DUT-8(Zn) exhibit a¹³C chemical shift of only about 170 ppm. In contrast, much higher values are observed for DUT-8(Ni) and especially DUT-8(Co). In the open pore state, the shift strongly depends on the solvent polarity in these two latter cases. The present contribution elucidates the reason for this solvent influence. It is concluded that the solvent mainly modifies the isotropic Fermi contact coupling constant for the excited high-spin states in DUT-8(Ni) and DUT-8(Co).</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101809"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40399789","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}

{"title":"Combining heteronuclear correlation NMR with spin-diffusion to detect relayed Cl–H–H and N–H–H proximities in molecular solids","authors":"Parth Raval ,&nbsp;Julien Trébosc ,&nbsp;Tomasz Pawlak ,&nbsp;Yusuke Nishiyama ,&nbsp;Steven P. Brown ,&nbsp;G.N. Manjunatha Reddy","doi":"10.1016/j.ssnmr.2022.101808","DOIUrl":"10.1016/j.ssnmr.2022.101808","url":null,"abstract":"<div><p>Analysis of short-to-intermediate range intermolecular interactions offers a great way of characterizing the solid-state organization of small molecules and materials. This can be achieved by two-dimensional (2D) homo- and heteronuclear correlation NMR spectroscopy, for example, by carrying out experiments at high magnetic fields in conjunction with fast magic-angle spinning (MAS) techniques. But, detecting 2D peaks for heteronuclear dipolar coupled spin pairs separated by greater than 3 Å is not always straightforward, particularly when low-gamma quadrupolar nuclei are involved. Here, we present a 2D correlation NMR experiment that combines the advantages of heteronuclear-multiple quantum coherence (HMQC) and proton-based spin-diffusion (SD) pulse sequences using radio-frequency-driven-recouping (RFDR) to probe inter and intramolecular ¹H-X (X = ¹⁴N, ³⁵Cl) interactions. This experiment can be used to acquire 2D ¹H{X}-HMQC filtered ¹H–¹H correlation as well as 2D ¹H-X HMQC spectra. Powder forms of dopamine·HCl and <span>l</span>-histidine·HCl·H₂O are characterized at high fields (21.1 T and 18.8 T) with fast MAS (60 kHz) using the 2D HMQC-SD-RFDR approach. Solid-state NMR results are complemented with NMR crystallography analyses using the gauge-including projector augmented wave (GIPAW) approach. For histidine·HCl·H₂O, 2D peaks associated with ¹⁴N–¹H–¹H and ³⁵Cl–¹H–¹H distances of up to 4.4 and 3.9 Å have been detected. This is further corroborated by the observation of 2D peaks corresponding to ¹⁴N–¹H–¹H and ³⁵Cl–¹H–¹H distances of up to 4.2 and 3.7 Å in dopamine·HCl, indicating the suitability of the HMQC-SD-RFDR experiments for detecting medium-range proximities in molecular solids.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101808"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0926204022000376/pdfft?md5=060bbed25bd8792da9bf6f8e36de193b&pid=1-s2.0-S0926204022000376-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40555369","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}

{"title":"19F Solid-state NMR characterization of pharmaceutical solids","authors":"Yong Du ,&nbsp;Yongchao Su","doi":"10.1016/j.ssnmr.2022.101796","DOIUrl":"10.1016/j.ssnmr.2022.101796","url":null,"abstract":"<div><p><span>Solid-state NMR has been increasingly recognized as a high-resolution and versatile spectroscopic tool to characterize drug substances and products. However, the analysis of pharmaceutical materials is often carried out at natural isotopic abundance and a relatively low drug loading in multi-component systems and therefore suffers from challenges of low sensitivity. The fact that fluorinated therapeutics are well represented in pipeline drugs and commercial products offers an excellent opportunity to utilize fluorine as a molecular probe for pharmaceutical analysis. We aim to review recent advancements of </span>¹⁹<span>F magic angle spinning NMR methods in modern drug research and development. Applications to polymorph screening at the micromolar level, structural elucidation, and investigation of molecular interactions at the Ångström to submicron resolution in drug delivery, stability, and quality will be discussed.</span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101796"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44659009","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}

{"title":"t1-noise elimination by continuous chemical shift anisotropy refocusing","authors":"Frédéric A. Perras ,&nbsp;Tian Wei Goh ,&nbsp;Wenyu Huang","doi":"10.1016/j.ssnmr.2022.101807","DOIUrl":"10.1016/j.ssnmr.2022.101807","url":null,"abstract":"<div><p><span>Due to their high gyromagnetic ratio, there is considerable interest in measuring distances and correlations involving protons, but such measurements are compounded by the simultaneous recoupling of chemical shift anisotropy (CSA). This secondary recoupling adds additional modulations to the signal intensities that ultimately lead to </span><em>t</em>₁-noise and signal decay. Recently, Venkatesh et al. demonstrated that the addition of CSA refocusing periods during ¹<span>H-X dipolar recoupling led to sequences with far higher stability and performance. Herein, we describe a related effort and develop a symmetry-based recoupling sequence that continually refocuses the </span>¹H CSA. This sequence shows superior performance to the regular and <em>t</em>₁<span>-noise eliminated D-HMQC sequences in the case of spin-1/2 nuclei and comparable performance to the later for half-integer quadrupoles.</span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101807"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49572288","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}

{"title":"High resolution solid state NMR in paramagnetic metal-organic frameworks","authors":"C.A. Klug ,&nbsp;M.W. Swift ,&nbsp;J.B. Miller ,&nbsp;J.L. Lyons ,&nbsp;A. Albert ,&nbsp;M. Laskoski ,&nbsp;C.M. Hangarter","doi":"10.1016/j.ssnmr.2022.101811","DOIUrl":"10.1016/j.ssnmr.2022.101811","url":null,"abstract":"<div><p>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.</p></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}

{"title":"Probing adsorption of water and DMF in UiO-66(Zr) using solid-state NMR","authors":"Florian Venel,&nbsp;Christophe Volkringer,&nbsp;Olivier Lafon,&nbsp;Frédérique Pourpoint","doi":"10.1016/j.ssnmr.2022.101797","DOIUrl":"10.1016/j.ssnmr.2022.101797","url":null,"abstract":"","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101797"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40395949","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}

{"title":"Long single pulse NQR for broad resonance lines","authors":"T.C.L. Ly,&nbsp;R. Yong,&nbsp;D.G. Miljak","doi":"10.1016/j.ssnmr.2022.101810","DOIUrl":"10.1016/j.ssnmr.2022.101810","url":null,"abstract":"<div><p><span>This paper describes the experimental application of long single pulses to strongly inhomogeneously broadened NQR spectral lines, where the pulse length significantly exceeds the transverse relaxation time. A</span>⁶³<span>Cu NQR resonance in the mineral covellite<span> (CuS) was used as an exemplar for study in this specific regime, which was motivated by the requirement to obtain useful signals in very large volume applications having radiofrequency power limitations. In this study, signal transients that followed the application of the long single pulses were measured over a large range of radiofrequency field<span> strength and pulse width. The results indicate effective generation of signal amplitudes. This is in contrast to previously reported studies involving long pulses applied to relatively narrow resonances. The results are found to be well described by simulations of the modified Bloch equations.</span></span></span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":"120 ","pages":"Article 101810"},"PeriodicalIF":3.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40521991","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}

{"title":"Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids","authors":"Scott L. Carnahan ,&nbsp;Yunhua Chen ,&nbsp;James F. Wishart ,&nbsp;Joseph W. Lubach ,&nbsp;Aaron J. Rossini","doi":"10.1016/j.ssnmr.2022.101785","DOIUrl":"10.1016/j.ssnmr.2022.101785","url":null,"abstract":"<div><p><span><span>In the past 15 years, magic angle spinning<span> (MAS) dynamic nuclear polarization<span><span> (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 </span>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, </span></span></span>histidine<span>, malic acid<span>, and malonic acid, and significant </span></span></span>¹H DNP enhancements of 32, 130, 19, and 11 were obtained, respectively, as measured by ¹H→¹³<span>C 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 </span>¹<span>H 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.</span></p></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}

{"title":"Multinuclear solid-state NMR: Unveiling the local structure of defective MOF MIL-120","authors":"Wanli Zhang ,&nbsp;Shoushun Chen ,&nbsp;Victor V. Terskikh ,&nbsp;Bryan E.G. Lucier ,&nbsp;Yining Huang","doi":"10.1016/j.ssnmr.2022.101793","DOIUrl":"10.1016/j.ssnmr.2022.101793","url":null,"abstract":"<div><p>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. ¹<span>H MAS NMR is used to characterize the hydrogen bonding in these MOFs, whereas </span>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.</p></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}

{"title":"Complete resonance assignment of a pharmaceutical drug at natural isotopic abundance from DNP-Enhanced solid-state NMR","authors":"Renny Mathew ,&nbsp;Ivan V. Sergeyev ,&nbsp;Fabien Aussenac ,&nbsp;Lydia Gkoura ,&nbsp;Melanie Rosay ,&nbsp;Maria Baias","doi":"10.1016/j.ssnmr.2022.101794","DOIUrl":"10.1016/j.ssnmr.2022.101794","url":null,"abstract":"<div><p>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.</p></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}