Diffusional Attenuation

NMR methods for the analysis of mixtures

“…7 In DOSY experiments, the separation is made according to the translational diffusion coefficients of the molecules. A pair of pulsed-field gradients (PFGs) separated by a delay is used to induce a diffusion-dependent attenuation of the peaks in the spectrum, 31,32 and the resulting diffusion weighted signal is analysed to extract both the component spectra and the diffusion coefficients. The concept of ''size-resolved NMR spectrometry'' was introduced as early as 1981 by Stilbs.…”

Making 1H–1H Couplings More Accessible and Accurate with Selective 2DJ NMR Experiments Aided by 13C Satellites

“…Stefan Berger proposed an elegant solution to this problem with the SERF experiment, in which frequency-selective pulses are combined with a 2D J-resolved (2DJ) experiment in such a way that only couplings to a chosen proton appear along the indirect dimension . Many further improvements have been proposed, including the simultaneous observation of the full spectral bandwidth by employing the Zangger–Sterk or PSYCHE elements, yielding the G-SERF and PSYCHEDELIC experiments, respectively . Selective 2DJ experiments are closely related to pure shift NMR, , and both are easily combined to homodecouple the chemical shift dimension, greatly improving spectral resolution. , This has allowed extraction of individual couplings, even for complex molecules or mixtures featuring very crowded 1 H NMR spectra. , …”