Deuterium NMR is
NMR spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic fiel ...
of
deuterium
Deuterium (or hydrogen-2, symbol or deuterium, also known as heavy hydrogen) is one of two Stable isotope ratio, stable isotopes of hydrogen (the other being Hydrogen atom, protium, or hydrogen-1). The atomic nucleus, nucleus of a deuterium ato ...
(
2H or D), an
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...
of
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
.
[
]
Deuterium is an isotope with
spin = 1, unlike hydrogen-1, which has spin = 1/2. The term deuteron NMR, in direct analogy to proton NMR, is also used.
[ Spiess, H. W. (1985). "Deuteron NMR – A new Tool for Studying Chain Mobility and Orientation in Polymers", ''Advances in Polymer Science'' 66: 23-57. DOI: 10.1007/3-540-13779-3_16.] Deuterium NMR has a range of
chemical shift
In nuclear magnetic resonance (NMR) spectroscopy, the chemical shift is the resonant frequency of an atomic nucleus relative to a standard in a magnetic field. Often the position and number of chemical shifts are diagnostic of the structure o ...
similar to
proton NMR
Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the struct ...
but with poor resolution, due to the smaller magnitude of the magnetic dipole moment of the deuteron relative to the proton. It may be used to verify the effectiveness of deuteration: a deuterated compound will show a strong peak in deuterium NMR but not proton NMR.
Deuterium NMR spectra are especially informative in the solid state because of its relatively small quadrupole moment in comparison with those of bigger quadrupolar nuclei such as chlorine-35, for example. This allows for the whole spectrum to be excited with practically achievable pulses of a few microseconds in duration. However, since the natural abundance of
2H is only 0.016%, the sample must usually be isotope enriched with
2H to achieve a sufficiently strong signal. For a given C-D moiety, the quadrupolar splitting in the
2H NMR spectrum depends in a simple way on the angle between the C-D bond and the applied static magnetic field.
Thus,
2H NMR can probe orientation distributions in partially ordered deuterated polymers.
Changes in C-D bond orientation due to molecular motions have pronounced effects on the spectral line shape.
One example is the use of deuterium NMR to study lipid membrane phase behavior.
References
Articles about solid-state deuterium NMR
{{NMR by isotope
Nuclear magnetic resonance