Abstract
The spin-lattice relaxation times (T1) of D and 17O nuclei of coordinated heavy water (D2O) molecules for Na+ and K+ in sodium bromide and potassium bromide dilute aqueous solutions were measured in the range of 5-50°C by means of NMR. The spin-lattice relaxation rates (R1=1/T1) varied linearly with the concentration up to 1mol/kg at a given temperature. The parallel (D) and the perpendicular (17O) rotational correlation times of coordinated D2O molecules for Na+ and K+ were determined. The ratio τ(D)/τ(17O) of the rotational correlation times of the coordinated D2O molecules was larger and smaller than unity for Na+ and K+, respectively, and was practically independent of temperature, which indicated that the rotational anisotropies of the coordinated D2O molecules was almost temperature independent.
