N.M.R. studies of lithium chloride and lithium bromide solutions in methanol-water mixtures

Abstract

Chemical shifts and transverse nuclear relaxation times of 35Cl and 81Br have been measured in mixed aqueous-methanol solutions of LiCl and LiBr. Electronic overlap between halide ions and adjacent solvent molecules and counter-ions is found to be the predominant, but not the only, mechanism producing chemical shifts. Relaxation rates of the two halogens are linear with viscosity over temperature for viscosity changes as large as twenty. An increase of the solvent methanol content promotes efficient relaxation probably due to relatively large correlation times associated with methanol reorientation.