98-17E

Configurational model for quantum statistical description of process of metal ion complex formation in water solution is proposed. Special attention is payed to formation of hydroxocomplexes. In the framework of the model determination of such chemical characteristics of reaction as Bjerrum function, partial mole fraction and formation constants is made. It is established that regions of existence of different complex forms at variation of solution pH reaction depend on differences of configuration energies and temperature. Existence of saturation effect which leads to sharp change of ligand concentration in solution when metal ion concentration crosses a certain value is found out. Dependence of this effect on temperature and other parameters of the system is investigated.