Multiplicity editing by 2D E-HSQC NMR spectroscopy: a product operator theory study

Abstract

Multiplicity editing of NMR signals into subsignals has become a useful technique to obtain simplified spectra for the separation of carbonyl groups in complex molecules. An E-HSQC experiment is an (1)H-detected, signal-edited and two-dimensional (2D) heteronuclear single quantum coherence (HSQC) NMR spectroscopy experiment. The product operator theory as a quantum mechanical method not only allows the confirmation of experimental results but also offers to make experimental suggestions on NMR experiments. In this study, analytical descriptions of the 2D E-HSQC NMR experiment for two different editing pulse blocks have been presented for a weakly coupled I S(n) (I = 1/2; S = 1/2, 1; n = 1, 2, 3) spin system by using the product operator theory. According to the obtained free induction decay (FID) values, theoretical predictions and experimental conditions have been suggested for spectral editing of (13)C/(15)NH, (13)C/(15)NH(2), (13)C/(15)NH(3) and (13)C/(15)ND, (13)C/(15)ND(2), (13)C/(15)ND(3) signals into subsignals.