Clean PDI-1 SQ: Suppression of HSQC artifacts in 2D proton-detected INADEQUATE spectra by pulse sequence redesign.

Proton-detected INADEQUATE NMR experiments are widely used for structure elucidation of small molecules, in particular the implementations that display C single-quantum rather than double-quantum frequencies in the indirect dimension of 2D spectra. But unfortunately, such spectra in addition to the desired H-C two-bond correlations also contain HSQC artifacts of comparable magnitude. The redesigned versatile experiment presented in this paper requires no compromise based on different C multiplicities and suppresses the HSQC artifacts that are a source of possible spectral misinterpretation. Demonstration of the new method is shown by applications to typical small molecules of different complexity.