The nature of the second dimension in 2D NMR: The Nature of the Second Dimension in 2D NMR

A two‐dimensional (2D) NMR spectrum is produced from the double Fourier Transform (FT) of two time domains, t 1 and t 2 . One of these domains, t 2 , is identical to the acquisition time used to collect a Free Induction Decay (FID) in one‐dimensional (1D) NMR spectroscopy. After performing the FTs of a series of these FIDs, an array of resonance lines is obtained whose amplitudes and phases are a function of t 1 . The t 1 domain is then composed of another series of “FIDs” that are related to those collected during t 2 . In this article, it is shown that in a heteronuclear‐J, δ gated‐decoupling experiment, the “FIDs” in the t 1 domain produce, after the FT, proton‐coupled spectra whose sum is identical to that obtained from a 1D carbon FID collected with no proton decoupling.