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Keywords:

  • optimization strategy;
  • J-compensation;
  • optimal control;
  • RDC;
  • COB-INEPT;
  • COB-HSQC

Robust experiments that cover a wide range of chemical shift offsets and J-couplings are highly desirable for a multitude of applications in small molecule NMR spectroscopy. Many attempts to improve individual aspects of the robustness of pulse sequence elements based on rational and numerical design have been reported, but a general optimization strategy to cover all necessary aspects for a fully robust sequence is still lacking.

In this article, a viable optimization strategy is introduced that covers a defined range of couplings, offsets, and B1-field inhomogeneities (COB) in a time-optimal way. Individual components of the optimization strategy can be optimized in any adequate way. As an example for the COB approach, we present the 1H − 13C-COB-INEPT with transfer of approximately 99% over the full carbon and proton bandwidth and 1JCH-couplings in the range of 120–250 Hz, which have been optimized using efficient algorithms derived from optimal control theory. The theoretical performance is demonstrated in a number of corresponding COB-HSQC experiments. Copyright © 2012 John Wiley & Sons, Ltd.