Self-diffusion coefficients obtained from proton-decoupled carbon-13 spectra for analyzing a mixture of terpenes

Mehdi Yemloul (1) , Vincent Castola (2) , Sébastien Leclerc (3) , Daniel Canet (1)

1 CRM2 - Cristallographie, Résonance Magnétique et Modélisations
2 SPE - Sciences pour l'environnement
3 LEMTA - Laboratoire d'Energétique et Mécanique Théorique et Appliquée

Sensitivity permitting, natural abundance 13 C offers a much better spectral resolution than proton NMR. This is due to an important chemical shift range and to proton decoupling conditions which yield one peak per carbon with practically no overlap. However, PGSE experiments, which lead to the diffusion coefficient associated with each peak, have scarcely been employed. In this paper, we present and compare different ways to access this quantity and we have effectively verified that, without any precaution, diffusion coefficients cannot be properly determined from standard procedures. The cause of such a failure is decoupling during the gradient pulses. We have used a very simple remedy which proved to be very successful on a model mixture of three monoterpenes and which appears as being of general applicability. 2 Introduction:

Domains: Theoretical and/or physical chemistry

Mehdi Yemloul, Vincent Castola, Sébastien Leclerc, Daniel Canet. Self-diffusion coefficients obtained from proton-decoupled carbon-13 spectra for analyzing a mixture of terpenes. Magnetic Resonance in Chemistry, 2009, 47, pp.635 - 640. ⟨10.1002/mrc.2442⟩. ⟨hal-01482094⟩