{"title":"Dipolar-order-based broadband adiabatic inversion as cross- polarization alternative in solid state Wideline NMR","authors":"Tamar Wolf, Lucio Frydman","doi":"10.1016/j.jmr.2025.107860","DOIUrl":null,"url":null,"abstract":"<div><div>Solid-state nuclear magnetic resonance (NMR) can shed light on atomic-level arrangements for most elements in the Periodic Table. This ability hinges on the possibility to overcome NMR's low sensitivity, particularly when dealing with unreceptive nuclei yielding ultra-wideline (>500 kHz) patterns from powdered samples. Herein, we present an experiment capable of enhancing the signals of such static samples, by transferring dipolar order from surrounding, highly polarized protons. The experiment, which we dub Dipolar-Order-based BRoadband Adiabatic INversion Cross-Polarization (DOBRAIN-CP), utilizes a Freeman-Kupče broadband inversion WURST pulse to perform CP over the wideline spectrum of the low receptivity species, while matching the low frequencies associated to <sup>1</sup>H<img><sup>1</sup>H dipolar fields. We present analytical and numerical analyses of the spin-dynamics of DOBRAIN-CP for spin-½ nuclei, as well as for quadrupolar spins. Experimental results are also presented for spin-½, integer and half-integer quadrupolar spins; these show that although DOBRAIN-CP delivers broadband excitation and sensitivity enhancement compared to direct excitations, it does not exceed the sensitivity enhancement of the BRAIN-CP variant based on Hartmann-Hahn matching. The power requirements for DOBRAIN-CP are extremely low, yet long dipolar-order lifetimes T<sub>1D</sub> are needed to support the DOBRAIN-CP build-up times.</div></div>","PeriodicalId":16267,"journal":{"name":"Journal of magnetic resonance","volume":"373 ","pages":"Article 107860"},"PeriodicalIF":2.0000,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of magnetic resonance","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1090780725000321","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
Solid-state nuclear magnetic resonance (NMR) can shed light on atomic-level arrangements for most elements in the Periodic Table. This ability hinges on the possibility to overcome NMR's low sensitivity, particularly when dealing with unreceptive nuclei yielding ultra-wideline (>500 kHz) patterns from powdered samples. Herein, we present an experiment capable of enhancing the signals of such static samples, by transferring dipolar order from surrounding, highly polarized protons. The experiment, which we dub Dipolar-Order-based BRoadband Adiabatic INversion Cross-Polarization (DOBRAIN-CP), utilizes a Freeman-Kupče broadband inversion WURST pulse to perform CP over the wideline spectrum of the low receptivity species, while matching the low frequencies associated to 1H1H dipolar fields. We present analytical and numerical analyses of the spin-dynamics of DOBRAIN-CP for spin-½ nuclei, as well as for quadrupolar spins. Experimental results are also presented for spin-½, integer and half-integer quadrupolar spins; these show that although DOBRAIN-CP delivers broadband excitation and sensitivity enhancement compared to direct excitations, it does not exceed the sensitivity enhancement of the BRAIN-CP variant based on Hartmann-Hahn matching. The power requirements for DOBRAIN-CP are extremely low, yet long dipolar-order lifetimes T1D are needed to support the DOBRAIN-CP build-up times.
期刊介绍:
The Journal of Magnetic Resonance presents original technical and scientific papers in all aspects of magnetic resonance, including nuclear magnetic resonance spectroscopy (NMR) of solids and liquids, electron spin/paramagnetic resonance (EPR), in vivo magnetic resonance imaging (MRI) and spectroscopy (MRS), nuclear quadrupole resonance (NQR) and magnetic resonance phenomena at nearly zero fields or in combination with optics. The Journal''s main aims include deepening the physical principles underlying all these spectroscopies, publishing significant theoretical and experimental results leading to spectral and spatial progress in these areas, and opening new MR-based applications in chemistry, biology and medicine. The Journal also seeks descriptions of novel apparatuses, new experimental protocols, and new procedures of data analysis and interpretation - including computational and quantum-mechanical methods - capable of advancing MR spectroscopy and imaging.