An equation for predicting the formation constants of hydroxo-metal complexes

Abstract

An equation has been developed to describe quantitatively the hydrolytic behaviour of most cations in the Periodic Table. This equation is a function only of the charge, ionic radius, and electronic structure, and takes the form shown below where log β_pq is the overall formation constant of the log β_pq=[(p– 1)(lnt₂)–q(lnt₁)]+[(p– 1)(Slp₂)–q(Slp₁)][g₁(z/r²+g₂)] species M_p(OH)_q. Int₁ and Slp₁, and Int₂ and Slp₂, are least-squares intercept and slope values of linear equations for monomers and polymers (depending on the structure type), respectively; z is the cationic charge, r is the ionic radius, and g₁ and g₂ are functions of the electronic structure. Since both g₁ and g₂ are themselves functions of z, the log β_pq values are necessarily a function of z²/r².