J-filter: An experiment to simplify and isolate specific signals in 1 H NMR spectra of complex mixtures based on

Karen V Góñez1, Juan Suárez García1, F Javier Sardina1

  • 1Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares, (CIQUS), Universidade de Santiago de Compostela, A Coruña, Spain.

PubMed

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When protons A and X are coupled, their nuclear spin energy levels are slightly modified. This is because the energy required to excite proton A to a spin state parallel to proton X is slightly different from the energy required for it to become anti-parallel to spin X. Consequently, there are two possible excitation frequencies for A (A1 and A2), depending on the spin state of X, and vice versa. The mutual nature of coupling implies that the difference between frequencies A1 and A2, indicated...
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