1. Purpose

The ¹⁹F nucleus (I = 1/2, natural abundance 100%) has nearly the same NMR sensitivity as the proton and may occupy the equivalent positions in an organic molecule. However, fluorine is much less widely distributed than hydrogen and hardly occurs at all in natural compounds, and therefore it does not have the same importance for NMR spectroscopy. On the other hand, it is exactly for this reason that the nuclide is very well suited for biochemical and medical applications, so that ¹⁹F NMR spectroscopy plays an increasing role in these areas [4,5]. Because of the proximity of the resonance frequencies of ¹H and ¹⁹F it is often possible to tune a proton probe-head to the ¹⁹F frequency, so that no special equipment, other than an ¹⁹F preamplifier, is needed for the standard experiment described here.

2. Literature

J. W. Emsley, L. Phillips, Prog. NMR Spectrosc. 1971, 7, 1–526.
J. W. Emsley, L. Phillips, V. Wray, Prog. NMR Spectrosc. 1976, 10, 83–756.
V. Wray, Annu. Rep. NMR Spectrosc. 1980, 10B, 1–507; ibid. 1983, 14, 1–406.
M. J. W. Prior, R. J. Maxwell, J. R. Griffith, NMR–Basic Principles and Progress 1992, 28, 101–130.
J. T. Gerig, Prog. NMR Spectrosc. 1994, 26, 293–370.
S. Berger, S. Braun, H.-O. Kalinowski, NMR Spectroscopy of the Non-Metallic Elements, Wiley, Chichester, 1997.
P. Bachert, Prog. NMR Spectrosc. 1998, 33, 1–56.

3. Pulse Scheme and Phase Cycle

Standard fluorine-19 pulse sequence and phase cycle

4. Acquisition

Time requirement: 5 min