Jump to main content
Jump to site search

Issue 32, 2009
Previous Article Next Article

Intermediate motions and dipolar couplings as studied by Lee–Goldburg cross-polarization NMR: Hartmann–Hahn matching profiles

Author affiliations

Abstract

In this article, we evaluate the use of simple Lee–Goldburg cross-polarization (LG-CP) NMR experiments for obtaining quantitative information of molecular motion in the intermediate regime. In particular, we introduce the measurement of Hartmann–Hahn matching profiles for the assessment of heteronuclear dipolar couplings as well as dynamics as a reliable and robust alternative to the more common analysis of build-up curves. We have carried out dynamic spin dynamics simulations in order to test the method’s sensitivity to intermediate motion and address its limitations concerning possible experimental imperfections. We further demonstrate the successful use of simple theoretical concepts, most prominently Anderson–Weiss (AW) theory, to analyze the data. We further propose an alternative way to estimate activation energies of molecular motions, based upon the acquisition of only two LG-CP spectra per temperature at different temperatures. As experimental tests, molecular jumps in imidazole methyl sulfonate, trimethylsulfoxonium iodide, and bisphenol A polycarbonate were investigated with the new method.

Graphical abstract: Intermediate motions and dipolar couplings as studied by Lee–Goldburg cross-polarization NMR: Hartmann–Hahn matching profiles

Back to tab navigation

Article information


Submitted
16 Apr 2009
Accepted
10 Jun 2009
First published
14 Jul 2009

Phys. Chem. Chem. Phys., 2009,11, 7036-7047
Article type
Paper

Intermediate motions and dipolar couplings as studied by Lee–Goldburg cross-polarization NMR: Hartmann–Hahn matching profiles

M. Fernando Cobo, K. Maliňáková, D. Reichert, K. Saalwächter and E. Ribeiro deAzevedo, Phys. Chem. Chem. Phys., 2009, 11, 7036
DOI: 10.1039/B907674C

Social activity

Search articles by author

Spotlight

Advertisements