Adiabatic z-filtered J-spectroscopy for absorptive homonuclear decoupled spectra

J-resolved NMR spectroscopy is a well-established method for measuring coupling constants or enhancing the resolution in homonuclear experiments. Classical J-spectra typically suffer from inevitable dispersive signal contributions and the occurrence of "ghost peaks" due to strong coupling effects. In this article, a J-resolved-type experiment with an adiabatic z-filter element for the selection of inphase magnetization and quadrature detection in the indirect dimension is presented. The phase-sensitive recording scheme allows the distinction of strong Coupling artefacts from symmetry relations and the full multiplet obtained by the experiment can be reduced by a simple pattern recognition algorithm. In addition to the J-resolved experiment, a second experiment is introduced that correlates strongly coupled spins. The possibility of homonuclear decoupling using the J-resolved experiment with the pattern recognition algorithm is demonstrated on a number of samples with a detailed description of potential strong coupling artefacts. (C) 2009 Elsevier Inc. All rights reserved.