Systematics of hydrolysis constants of tetravalent actinide ions

Systematic trends of mononuclear and polynuclear hydrolysis constants of tetravalent actinide ions were analyzed by using an electrostatic hard sphere model. The effective charges of actinide ions were introduced into the model by considering possible contributions non-electrostatic interactions of actinide ions in addition to those of ordinary electrostatic ones. The systematic trends of hydrolysis constants were well fitted by the present model, and the parameter values such as the effective charges of actinide ions were determined. Some predictions were made and discussed in comparison with the solubility curves of tetravalent actinides. (author)