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Article
Fast Acquisition of Proton Detected HETCOR Solid‐State NMR Spectra of Quadrupolar Nuclei and Rapid Measurement of NH Bond Lengths by Frequency Selective HMQC and RESPDOR Pulse Sequences
Chemistry–A European Journal
  • Anuradha V. Wijesekara, Iowa State University
  • Amrit Venkatesh, Iowa State University
  • Bryan J. Lampkin, Iowa State University
  • Brett VanVeller, Iowa State University
  • Joseph W. Lubach, Genentech Inc.
  • Karthik Nagapudi, Genentech Inc.
  • Ivan Hung, Center for Interdisciplinary Magnetic Resonance
  • Peter L. Gor’kov, Center for Interdisciplinary Magnetic Resonance
  • Zhehong Gan, Center for Interdisciplinary Magnetic Resonance
  • Aaron J. Rossini, Iowa State University and Ames Laboratory
Document Type
Article
Disciplines
Publication Version
Accepted Manuscript
Publication Date
4-21-2020
DOI
10.1002/chem.202000390
Abstract

Fast magic angle spinning (MAS), frequency selective (FS) heteronuclear multiple quantum coherence (HMQC) experiments which function in an analogous manner to solution SOFAST HMQC NMR experiments, are demonstrated. Fast MAS enables efficient FS excitation of 1 H solid‐state NMR signals. Selective excitation and observation preserves 1 H magnetization, leading to a significant shortening of the optimal inter‐scan delay. Dipolar and scalar 1 H{ 14 N} FS HMQC solid‐state NMR experiments routinely provide 4‐ to 9‐fold reductions in experiment times as compared to conventional 1 H{ 14 N} HMQC solid‐state NMR experiments. 1 H{ 14 N} FS resonance‐echo saturation‐pulse double‐resonance (RESPDOR) allowed dipolar dephasing curves to be obtained in minutes, enabling the rapid determination of NH dipolar coupling constants and inter‐nuclear distances. 1 H{ 14 N} FS RESPDOR was used to assign multicomponent active pharmaceutical ingredients (APIs) as salts or cocrystals. FS HMQC also provided enhanced sensitivity for 1 H{ 17 O} and 1 H{ 35 Cl} HMQC experiments on 17 O labeled Fmoc‐alanine and histidine hydrochloride monohydrate, respectively. FS HMQC and FS RESPDOR experiments will provide access to valuable structural constraints from materials that are challenging to study due to unfavorable relaxation times or dilution of the nuclei of interest.

Comments

This is a manuscript of an article published as Wijesekara, Anuradha V., Amrit Venkatesh, Bryan J. Lampkin, Brett VanVeller, Joseph W. Lubach, Karthik Nagapudi, Ivan Hung, Peter L. Gor’kov, Zhehong Gan, and Aaron James Rossini. "Fast Acquisition of Proton Detected HETCOR Solid‐State NMR Spectra of Quadrupolar Nuclei and Rapid Measurement of NH Bond Lengths by Frequency Selective HMQC and RESPDOR Pulse Sequences." Chemistry–A European Journal (2020). DOI: 10.1002/chem.202000390. Posted with permission.

Copyright Owner
WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Language
en
File Format
application/pdf
Citation Information
Anuradha V. Wijesekara, Amrit Venkatesh, Bryan J. Lampkin, Brett VanVeller, et al.. "Fast Acquisition of Proton Detected HETCOR Solid‐State NMR Spectra of Quadrupolar Nuclei and Rapid Measurement of NH Bond Lengths by Frequency Selective HMQC and RESPDOR Pulse Sequences" Chemistry–A European Journal (2020)
Available at: http://works.bepress.com/aaron-rossini/84/