LAUSR

The development of new tools to improve the quality of nuclear magnetic resonance (NMR) spectra is a challenging task. The concept of “perfect NMR” includes the design of robust pulse sequences that allow an investigator to obtain undistorted pure in‐phase signals, with pure absorption lineshapes that are free of phase anomalies derived from undesired J modulations. Here, alternative NMR building blocks to the spin‐echo that are based on a general double SE module, known as a perfect‐echo, are reviewed. Several implementations to minimize/remove unwanted dispersive contributions in homonuclear and heteronuclear NMR experiments are described and illustrated with some examples of broad interest for small molecules.