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The NMR Spectra of Samples Dissolved in Liquid-Crystalline Phases. Automatic Analysis with the Aid of Multiple-Quantum Spectra

✍ Scribed by G. Celebre; F. Castiglione; M. Longeri; J.W. Emsley

Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
152 KB
Volume
121
Category
Article
ISSN
1064-1858

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✦ Synopsis

A new strategy is described for analyzing the NMR spectra of spectra, depend on the same Hamiltonian, and so contain molecules dissolved in liquid-crystalline phases. The multiplethe same information. The computation of the frequencies quantum spectra which involve a change in the magnetic quanof the transitions in NQ spectra can be simplified compared tum number m by N 0 1, where N is the maximum possible, to the 1Q case for the higher values of N, but in general, are recorded and analyzed automatically starting from a paramthe computational problem is not reduced, and indeed is eter set having all the spectral parameters set to zero. The results increased if intensities are computed (10).

of such an analysis are then used as the starting parameters in

The normal method of analyzing the 1Q spectra from an analysis of the single-quantum spectrum using an automatic liquid-crystalline samples is the same as for isotropic phase analysis procedure. The method is illustrated by analyses of the sample (11). A spectrum is simulated from a trial set of proton spectra of bromobenzene ( five spins ) and ethynylbenzene parameters (chemical shifts, d i , scalar couplings, J ij , and and naphthaquinone ( six spins ) dissolved in nematic solvents.

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