Rotational and Translational Diffusion and Dipolar Spin Relaxation in Diamagnetic Electrolyte Solutions

The present paper starts from the question to what an extent correlation times for the molecular rotation (or reorientation times) in the hydration shells may be derived from the nuclear magnetic relaxation times of the protons in diamagnetic electrolyte solutions. The intramolecular relaxation rate of the protons in aqueous electrolyte solutions is calculated. Use is made of a model in which the reorientation times in the hydration shells and the free water are different. Moreover, the various regions of the solution are characterized by different rotation‐step constants. The treatment is closely related to a work by Beckert and Pfeifer concerning the same subject. The results of the theorie are discussed with regard to the above mentioned question. Further, the calculation of the self‐diffusion coefficient of the water molecules in an electrolyte solution is described. The theory given is a random‐walk treatment, the procedure is similar to that presented for the rotational motion in the first part of this paper. In the last section the problem of the separation of the electrolyte solution in hydration shells and free water in its special concern to the rotational correlation times is dealt with.