Comparison of 1H-19F two-dimensional NMR scalar coupling correlation pulse sequences

The effectiveness of hetero-COSY, HETCOR, HMQC, and HSQC two-dimensional NMR pulse sequences for detection of F-19-H-1 correlations by scalar coupling was evaluated on monofluorinated and polyfluorinated test compounds. All four of these sequences were effective in observing H-1-F-19 correlations, using either F-19 or H-1 as the observe nucleus. All four sequences were amenable, to some degree, to adjustment to observe larger or smaller couplings preferentially. A 1/2J echo filter was effectively applied to remove artifacts from (2)J(FF) strong coupling. The HETCOR experiments afforded the best overall combination of sensitivity, resolution and selectivity for J(HF). Copyright (c) 2014 John Wiley & Sons, Ltd.