Chlorine-35 NMR Study of the Shifts and Line Shapes of Some Liquid Inorganic Chlorides

Abstract

The chemical shifts and linewidths of a series of 18 liquid inorganic chlorides have been measured using 35Cl broadline NMR techniques. The chemical shifts vary from 120–950 ppm downfield from the chloride ion. Assuming the mean excitation energies of these compounds are equal, a rough correlation of shift with quadrupole coupling constants is obtained for the nontransitional metal chlorides. The shifts of the transitional metal chlorides do not correlate with the quadrupole coupling constants, suggesting dπ–pπ interactions. The full linewidths at half‐maximum intensity vary from 0.15–48 G. The observed widths, corrected for viscosity and molecular dimensions, correlate reasonably well with the quadrupole coupling constants. The observed correlation times τ c are about a factor of 10 shorter than those calculated with the Debye–Einstein equation. The line shapes and widths were determined using a computer program that resolved the experimental spectra in terms of overlapping Lorentzian functions.