1H spin-lattice NMR relaxation in the presence of residual dipolar interactions - Dipolar relaxation enhancement

Danuta Kruk; Pawel Rochowski; Malgorzata Florek-Wojciechowska; Pedro José Sebastião; David J Lurie; Lionel M Broche

doi:10.1016/j.jmr.2020.106783

¹H spin-lattice NMR relaxation in the presence of residual dipolar interactions - Dipolar relaxation enhancement

J Magn Reson. 2020 Sep:318:106783. doi: 10.1016/j.jmr.2020.106783. Epub 2020 Jul 13.

Authors

Danuta Kruk¹, Pawel Rochowski², Malgorzata Florek-Wojciechowska³, Pedro José Sebastião⁴, David J Lurie⁵, Lionel M Broche⁵

Affiliations

¹ Faculty of Mathematics and Computer Science, University of Warmia & Mazury in Olsztyn, Słoneczna 54, 10-710 Olsztyn, Poland. Electronic address: danuta.kruk@matman.uwm.edu.pl.
² Faculty of Mathematics and Computer Science, University of Warmia & Mazury in Olsztyn, Słoneczna 54, 10-710 Olsztyn, Poland.
³ Department of Physics & Biophysics, University of Warmia and Mazury in Olsztyn, Oczapowskiego 4, 11-041 Olsztyn, Poland.
⁴ Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
⁵ Bio-Medical Physics, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom.

PMID: 32755749
DOI: 10.1016/j.jmr.2020.106783

Abstract

A model of spin-lattice relaxation for spin-1/2 nuclei in the presence of a residual dipole-dipole coupling has been presented. For slow dynamics the model predicts a bi-exponential relaxation at low frequencies, when the residual dipole-dipole interaction dominates the Zeeman coupling. Moreover, according to the model a frequency-specific relaxation enhancement, referred to as Dipolar Relaxation Enhancement (DRE) in analogy to the Quadrupole Relaxation Enhancement (QRE) is expected. The frequency position of the relaxation maximum is determined by the amplitude of the residual dipole-dipole interaction. Experimental examples of relaxation properties that might be attributed to the DRE are presented. The DRE effect has the potential to be exploited, in analogy to QRE, as a unique source of information about molecular dynamics and structure.

Keywords: Dynamics; NMR; Relaxation.

Publication types

Research Support, Non-U.S. Gov't