Fluorine-19 NMR
Encyclopedia
Fluorine-19 nuclear magnetic resonance
Nuclear magnetic resonance
Nuclear magnetic resonance is a physical phenomenon in which magnetic nuclei in a magnetic field absorb and re-emit electromagnetic radiation...

is an analytical technique. 19F has a spin of 1/2, and a relative abundance of 100 % and a high magnetogyric ratio
Magnetogyric ratio
In physics, the gyromagnetic ratio of a particle or system is the ratio of its magnetic dipole moment to its angular momentum, and it is often denoted by the symbol γ, gamma...

, making measurements very fast (comparable with 1H NMR). Integrals are reliable due to the lack of a nuclear Overhauser effect
Nuclear Overhauser effect
The Nuclear Overhauser Effect is the transfer of nuclear spin polarization from one nuclear spin population to another via cross-relaxation. It is a common phenomenon observed by nuclear magnetic resonance spectroscopy. The theoretical basis for the NOE was described and experimentally verified...

 (fluorine forms one bond only). Fluorine-containing compounds are occasionally encountered in organic chemistry (fluorinated compounds are popular in pharmaceutical applications), and in inorganic chemistry (e.g. the trifluoroacetate anion or counter-ligand).

The reference compound for 19F is CFCl3
Trichlorofluoromethane
Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon. It is a colorless, nearly odorless liquid that boils at about room temperature.- Uses :It was the first widely used refrigerant...

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