Magnetic susceptibility measurement by NMR: 2. The magnetic susceptibility of NMR solvents and their chemical shifts.

Most routine 1H NMR spectroscopy references the chemical shift of TMS to zero. However, its chemical shift varies with solvent and environmental conditions. Chemical shifts and magnetic susceptibilities of TMS and several NMR solvents are accurately measured over a range of temperatures. Methods for improving the measurements of chemical shifts and magnetic susceptibilities are developed and demonstrated. This makes it possible to compare chemical shifts of compounds between solvents, improving the accuracy of solvent effect measurements. The effects of polarizability and aromaticity on the chemical shift of TMS are shown. The molar magnetic susceptibilities of the deuterated solvents are similar to those of the regular protiated solvents.