You are here

Enhancing the resolution of H-1 and C-13 solid-state NMR spectra by reduction of anisotropic bulk magnetic susceptibility broadening

TitleEnhancing the resolution of H-1 and C-13 solid-state NMR spectra by reduction of anisotropic bulk magnetic susceptibility broadening
Publication TypeJournal Article
Year of Publication2017
AuthorsHanrahan, MP, Venkatesh, A, Carnahan, SL, Calahan, JL, Lubach, JW, Munson, J, Rossini, AJ
JournalPhysical Chemistry Chemical Physics
Volume19
Pagination28153-28162
Date Published11
Type of ArticleArticle
ISBN Number1463-9076
Accession NumberWOS:000413778800027
Keywordschemistry, coherence, correlation spectroscopy, crystal-structure prediction, disordered solids, dynamic nuclear-polarization, form-ii, inhomogeneous fields, mas nmr, physics, reference deconvolution, transfer echoes, zero-quantum coherences
Abstract

te NMR spectra obtained from 2D H-1-C-13 HETCOR NMR spectra show that the HETCOR spectrum directly increases resolution by a factor of 1.5 to 8. The direct gain in resolution is determined by the ratio of the inhomogeneous C-13/H-1 linewidth to the homogeneous H-1 linewidth, with the former depending on the magnitude of the ABMS broadening and the strength of the applied field and the latter on the efficiency of homonuclear decoupling. The direct gains in resolution obtained using the 2D HETCOR experiments are better than that obtained by dilution. For solids with long proton longitudinal relaxation times, dynamic nuclear polarization (DNP) was applied to enhance sensitivity and enable the acquisition of 2D H-1-C-13 HETCOR NMR spectra. 2D H-1-C-13 HETCOR experiments were applied to resolve and partially assign the NMR signals of the form I and form II polymorphs of aspirin in a sample containing both forms. These findings have important implications for ultra-high field NMR experiments, optimization of decoupling schemes and assessment of the fundamental limits on the resolution of solid-state NMR spectra.

DOI10.1039/c7cp04223j
Custom 1

AL Royalty