Improved excitation uniformity in multiple‐quantum NMR experiments of mixtures

Multiple‐quantum ¹H NMR spectroscopy has been finding a renewed interest for its possible applications in the analysis of mixtures of small molecules, due to its simplification properties. A crucial aspect of this application of multiple‐quantum NMR is the sensitivity of the spectrum intensity to the molecular structure and to the parameterization of the experiment, which could result in the missing of some components. We demonstrate that a general scheme to overcome this drawback consists in varying the experiment parameterizations over a small number of values, selected according the values of the couplings and the relaxation rates. Copyright © 2013 John Wiley & Sons, Ltd.