Analyses of the complex proton NMR spectra: Determination of anisotropic proton chemical shifts of oriented molecules by a two dimensional experiment

Mavinkurve, Raghav G and Deepak, Vinay HS and Ramanathan, KV and Suryaprakash, N (2007) Analyses of the complex proton NMR spectra: Determination of anisotropic proton chemical shifts of oriented molecules by a two dimensional experiment. In: Journal of Magnetic Resonance, 185 (2). pp. 240-246.

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Abstract

NMR spectra of molecules oriented in the liquid crystalline media provide information on the molecular structure and order parameter. However, the numerical iterative analysis of the proton spectra of strongly coupled spins is difficult and time consuming. Such analysis is simplified if nearly accurate starting parameters are available. One such parameter is the chemical shift which in the oriented media is very different from the isotropic values due to anisotropic contributions. In this study, we have explored the possibility of obtaining chemical shifts in the oriented phase to aid the analysis of the spectra. A two dimensional experiment in which FSLG decoupling employed during the $t_1$ period eliminates the homonuclear dipolar couplings and retains only the chemical shifts has been implemented. Experiments on the molecule cis,cis-mucononitrile demonstrate that the chemical shifts obtained by this procedure are nearly the same as the chemical shifts derived by iterative analysis of the one dimensional spectrum of the molecule following the standard procedure. The method has also been used to analyse the spectrum of 1-iodopropane using the chemical shifts obtained from the proposed experiment as the starting parameters.

Item Type:	Journal Article
Publication:	Journal of Magnetic Resonance
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	NMR;Dipolar couplings;Lee Goldburg;Decoupling;Mucononitrile;Iodopropane
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	16 Oct 2007
Last Modified:	19 Sep 2010 04:39
URI:	http://eprints.iisc.ac.in/id/eprint/11735

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