Experimental results for the nuclear magnetic relaxation rate of Li7 in H2O and D2O solutions of LiCl, LiBr, and LiI are reported. The relaxation contribution due to magnetic dipole‐dipole interaction is separated, the rotational correlation time of the vector connecting the cation with the 1st hydration water is determined and the latter time is compared with the correlation time of the H – H vector in H2O of the 1st hydration sphere. Both times are not equal which indicates that the water molecules rotates about the Li – O axis. The quadrupolar contribution to the relaxation rate of Li7 is interpreted in terms of a break‐down of cubic symmetry in the hydration sphere as the salt concentration increases. Self‐diffusion data of Li+ in LiCl, LiBr, and LiI solutions are as well reported and a structural interpretation of the concentration dependence is given. Proton relaxation rates of AlCl3 solutions containing 100% H2O and of those which contain only a very small amount of HDO in D2O are given. The evaluation yields the result that the correlation times of the two vectors in the hydration sphere as described above are equal for Al3+. Some structural consequences are described, proton relaxation rates in Ga3+ solutions, Al27 relaxation rates in AlCl3 solutions, and water self‐diffusion coefficients in AlCl3 solutions are reported.

Proton relaxation rates in solutions MnCl2-CD3OH and MnCl2-C2D5OH are reported and from these data rotational correlation times for the solvation complexes are determined. Proton and deuteron relaxation rates for the hydroxyl, methylene, and methyl group in solutions of Mg(C104)2, CaCl2, NaC104, Nal, and KI in methyl alcohol and ethyl alcohol are reported, and correlation times for the various groups are determined. The various correlation times are compared with one another and, in those cases where they differ for a given solvation complex, intermolecular or intramolecular motions are postulated. The results are also compared with predictions derived from pertinent theories currently available. It is found that the description of the internal motions by the theory is not satisfactory in all cases.

ABSTRACT7 Li and 23 Na relaxation times in aqueous solution of Li+ and Na+ in the presence of an increasing amount of Mn2+ are reported. From these measurements the cation-cation pair distribution function has been calculated. A distance ofapproach between Li+ (or Na +)and Mn 2 + of ~4.5A has been found.The intermolecular proton relaxation rates of the acids CH 3 COOD, CH 3 CD 2 COOD, and CD 3 CH 2 COOD dissolved in water (D 2 0) are presented and from these data simple acid-acid pair distribution functions are constructed. Association has been detected from excess intermolecular proton-proton interactions. In the solution of propionic acid the association is stronger as seen from the methylene group than from the methyl group.In the pure alcohols CD 3 0H and C 2 D 5 0H and their mixtures with inert solvents intermolecular proton relaxation is entirely of rotational character and permits conclusions concerning the depth of the potential characterizing the pair distribution function.

Fliissiyk eilen I Kernniagnetische Relaxation I Losungen / Magnetische Kernresonaris lntermolecular proton magnetic relaxation rates of the methyl and hydroxyl group of acetic acid involving the magnetic interaction among the various groups are reported. The data are given as a function of the mole fraction in the mixture acetic acid/CCI,. From these experimental results model atomic pair distribution functions and model molecular pair distribution functions are derived. It is shown that in the pure acid OH and CH, never approach closely towards one another. At mole fractions x2 5 0.3 the classical dimer can be observed which, however, appears in a more or less folded form.

Longitudinal relaxation times 7\ of the various protons in the system CH3COOH-C6Hi2 have been measured as a function of mixture composition. From these data intramolecular relaxation rates and intermolecular proton relaxation rates arising from interactions among the proton-carrying groups are extracted. The experimental results have been evaluated to yield orientation dependent model molecular pair distribution functions involving pairs of acid molecules, pairs of cyclohexane molecules, and acid-cyclohexane pairs.