Misono softness parameter

For an introduction to Lewis acids and the Misono softness parameter, see, e.g.. Chap. 3 in G. Sposito, The Thermodynamics of Soil Solutions. Clarendon Press, Oxford, 1981. 

Figure 4.4. The relation between the standard Gibbs energy for Li"" — M"" exchange on montmorillonite and the Misono softness parameter of (M = Na, K, Rb, Cs). ...

The softness parameter of Misono and Saito (Y ) (Misono and Saito 1970) is based on the use of a regression model where the log of stability constants of halogeno-complexes of metal ions (Log k) is a function of two parameters. One parameter corresponds to hardness (X) and the other to softness (Y),... 

M. Misono, E. Ochiai, Y. Saito, and Y. Yoneda, A new dual parameter scale for the strength of Lewis acids and bases with evaluation of their softness, J. Inorg. Nucl. Chem. 29 2685 (1967). 

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