Quadrupolar Relaxation of ²⁷Al in Aqueous Solution. III. Discussion on Motions of Hydration Water Molecules

Abstract

The chemical potential for the complex consisting of the water molecules co-ordinated to Al⁺⁺⁺ in water is discussed. The use of the data obtained in a previous paper Part II [A. Takahashi: J. Phys. Soc. Japan 43 (1977) 976.] for the rate constants for the motions of the hydration water molecules leads to a reasonable conclusion that when one water molecule in the second layer in the complex transfers to the adjacent equilibrium position in the solvent water, the number of the hydrogen bond between this molecule and the solvent water molecule increases by one bond, which forms a momentary stable state in the system. This conclusion confirms that several approximations made in Part II for the rate constants of the molecular motions are valid.