Inorganic Chemistry, Vol.43, No.7, 2422-2426, 2004
Structure of the UO22+-SO42- ion pair in aqueous solution
The structure of the ion pairs formed in aqueous uranyl sulfate solutions has been investigated with high-energy X-ray scattering. Sulfate binds to the uranyl as a monodentate ligand in equimolar solutions. The geometry of the ion pair is very similar to configurations found in crystalline structures; in particular, the U-O-S angle is bent in solution as well as in the solid state. It can therefore be concluded that an U-O-S angle of 1430 is an intrinsic property of the uranyl sulfate bond and not due to packing effects or interaction with the water in the primary solvation shell.