Deuterated solvents are used to dissolve analytes when performing solution-phase NMR[1]. Substitution of the solvent's 1H atoms with deuterium (2H atoms) yields solvents which do not interfere with the acquisition of the 1H NMR spectra. They are thus isotopologues of standard organic solvents.
Manufacture
editThe inherent difficulty in producing high levels of isotopic enrichment and maintaining high purity make deutero-solvents significanlty more costly than their isotopologues.
Role in magnetic-field stabilisation
editDeuterated solvents also allow for simultaneous calibration to be undertake to ensure stability of the magnetic field of the NMR spectrometer, this being commonly referred to as the "lock".
Safety
editDue to the kinetic isotope effect the difference between protium and deuterium may result in significant differences in the toxicity of deuterated versus non-deuterated solvents. A most obvious and extreme example being that of D2O (Heavy water) which could be potentially harmful in large enough quantities.
Deuterium-exchange
editDeuterated analogues of protic solvents play another important role in structural elucidation. Rapid exchange of labile protons in an analyte may be possible with those found in solution, for example with a solution of ethanol in water the ethanolic proton can dissociate and be replaced by another proton previously found in a water molecule. If ethanol was mixed with a large amount of D2O however, exchange of the alcohol protons for deuterium atoms quickly results in the loss of the OH peak in the NMR spectra of ethanol. This allows for a test for exchangeable protons to be performed very simply, being referred to as a "D2O-shake".
d1-methanol (MeOD) is also commonly used for such work, its incomplete deuteration versus d4-methanol making it significantly less expensive.
References
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