Cross- and axial-peak intensities in 2D-SLF experiments based on cross-polarization—The role of the initial density matrix

Das, Bibhuti B and Ajithkumar, TG and Sinha, Neeraj and Opella, Stanley J and Ramanathan, KV (2007) Cross- and axial-peak intensities in 2D-SLF experiments based on cross-polarization—The role of the initial density matrix. In: Journal of Magnetic Resonance, 185 (2). pp. 308-317.

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Abstract

Simulations and experiments on simple oriented systems have been used to estimate the relative ratio of cross-peak to axial-peak intensities in 2D-SLF experiments based on dipolar oscillations during cross-polarization (CP). The density matrix prior to dipolar evolution is considered and for an isolated spin pair, it is shown that direct calculations of the ratios match well with simulations and experimental results. Along with the standard CP pulse sequence, two other pulse sequences namely CP with polarization inversion (PI–CP) and another novel variation of the standard CP experiment (EXE-CP) reported recently have been considered. Inclusion of homonuclear dipolar coupling has been observed to increase the axial-peak intensities. In combination with Lee–Goldburg (LG) decoupling, experiments on an oriented liquid crystalline sample have been carried out and the performance of the pulse schemes have been compared. The applicability of the new pulse sequence for different samples and different nuclei is discussed. Such studies are expected to lead to a better understanding of the experiments and to the design of useful pulse sequences.

Item Type:	Journal Article
Publication:	Journal of Magnetic Resonance
Publisher:	Elsevier Inc.
Additional Information:	Copyright of this article belongs to Elsevier Inc.
Keywords:	SLF;Oriented molecules;PISEMA;Cross polarization
Department/Centre:	Division of Chemical Sciences > Sophisticated Instruments Facility (Continued as NMR Research Centre) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Jan 2008
Last Modified:	19 Sep 2010 04:39
URI:	http://eprints.iisc.ac.in/id/eprint/11736

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