529: Experimentally Determined Densities of Deuterated Solvents for Use in NMR Spectroscopy

Presenter(s)

Andrew Norfleet

Abstract or Description

Nuclear Magnetic Resonance (NMR) is a universally recognized spectroscopic technique for the determination of chemical structure. A critical component of NMR analysis involves deuterated isotopologues of laboratory solvents, which establish a frequency lock for the instrument. While qualitatively establishing sample characteristics only requires the deuterons' presence, quantitative techniques require determining the concentration of species in solution, a function of temperature. This relationship is significant to the fields of kinetics and thermodynamics. Surprisingly, current literature fails to list deuterated solvents' density for temperatures beyond ambient, if at all. This work seeks to elucidate those properties and draw comparisons between the deuterated solvents and their natural variants. Data were collected for twelve liquid NMR solvents in a vibrating tube densitometer across a temperature range of 5 to 95 °C in five-degree intervals. Comparisons were drawn between the values presented in this work and the corresponding non-deuterated species' literature values. Notably, the molar volumes' trends demonstrate that the change in density varies across temperature and is not accounted for by the difference in the molecular masses.