Multiple Parallel 2D NMR Acquisitions in a Single Scan

Abstract

Faster than ultrafast: A new sequence combining “ultrafast” single‐shot 2D NMR and parallel receiving technologies is presented. The potential of the resulting parallel ultrafast 2D spectroscopy (PUFSY) NMR experiments is shown by simultaneously collecting homo‐ and heteronuclear correlation information for 1H–19F systems (see picture) and a 1H–31P system.

Monitoring organic reactions by UF‐NMR spectroscopy

“…With the tandem approach, UF‐HMBC allows differentiation among the intermediates present, while UF‐TOCSY affords structural details from their proton connectivity. The UF‐TOCSY/HMBC methodology can be easily applied directly in spectrometers with a single receiver and therefore represents a simple alternative to UF‐PUFSY for the multiple parallel acquisition of UF 2D NMR spectra in a single scan …”

Fast experiments for structure elucidation of small molecules: Hadamard NMR with multiple receivers

“…Note that C‐13 nuclei only experience the gradient G 4 while protons experience the sum of both gradients, G 3 + G 4 . This allows using gradient selection for both, the H‐1 and C‐13 detected spectra, as described previously . Thus both 2D H–H COSY and 2D H–C long‐range HETCOR spectra can be acquired in parallel using a single scan per t 1 increment.…”

“…In sampling limited cases the experiment time can be further reduced by combining the multiple receiver experiments with other fast techniques, such as spatial encoding (ultra‐fast NMR), Hadamard encoding, non‐uniform sampling or computer‐optimized folding . In small molecule NMR the Hadamard encoding method has two important advantages over other fast techniques—(a) relatively few increments are usually required and (b) it benefits from sqrt(2) sensitivity advantage as compared to Fourier transform based methods.…”

Parallel NMR spectroscopy with simultaneous detection of 1H and 19F nuclei

“…The ultra‐fast (UF) NMR spectroscopy introduced by Frydman et al is based on spatial frequency encoding in the F1 domain, which replaces the traditional t 1 evolution period achieving two‐dimensional NMR correlation spectroscopy in a single scan. The UF version of the PANSY H‐H COSY and H‐F COSY experiment is shown in Fig. .…”

“…The multi‐receiver technology allows combining the best of both worlds making 1 H and 19 F detected NMR experiments even more efficient. Yet the multi‐receive experiments that have been developed for spin systems involving two or more abundant high‐sensitivity nuclei remain underutilized . We show that in sampling limited situations the use of parallel acquisition can potentially increase throughput in NMR laboratories working with fluorine containing compounds by at least a factor of two.…”