17O NMR relaxation measurements for investigation of molecular dynamics in static solids using sodium nitrate as a model compound

Liliya Vugmeyster; Riqiang Fu; Dmitry Ostrovsky

doi:10.1016/j.ssnmr.2024.101976

¹⁷O NMR relaxation measurements for investigation of molecular dynamics in static solids using sodium nitrate as a model compound

Solid State Nucl Magn Reson. 2024 Nov 20:134:101976. doi: 10.1016/j.ssnmr.2024.101976. Online ahead of print.

Authors

Liliya Vugmeyster¹, Riqiang Fu², Dmitry Ostrovsky³

Affiliations

¹ Department of Chemistry, University of Colorado Denver, Denver, CO, 80204, USA. Electronic address: LILIYA.VUGMEYSTER@UCDENVER.EDU.
² National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA.
³ Department of Mathematics, University of Colorado Denver, Denver, CO, 80204, USA.

PMID: 39581174
DOI: 10.1016/j.ssnmr.2024.101976

Abstract

¹⁷O NMR methods are emerging as a powerful tool for determination of structure and dynamics in materials and biological solids. We present experimental and theoretical frameworks for measurements of ¹⁷O NMR relaxation times in static solids focusing on the excitation of the central transition of the ¹⁷O spin 5/2 system. We employ ¹⁷O-enriched NaNO₃ as a model compound, in which the nitrate oxygen atoms undergo 3-fold jumps. Rotating frame (T_1ρ), transverse (T₂) and longitudinal (T₁) relaxation times as well as line shapes were measured for the central transition in the 280 to 195 K temperature range at 14.1 and 18.8 T field strengths. We conduct experimental and theoretical comparison between different relaxation methods and demonstrate the advantage of combining data from multiple relaxation time and line shape measurements to obtain a more accurate determination of the dynamics as compared to either of the techniques alone. The computational framework for relaxation of spin 5/2 nuclei is developed using the numerical integration of the Liouville - von Neumann equation.