Uranium (6) complexing with linear and cyclic polyphosphates

Uranium (6) complexing with pyro-, tripoly-, trimeta-, tetrameta- and hexametaphosphateions has been studied by the metal-indicator method in the uranyl-arsenazo 1-sodium polyphosphate system. Stale acidocomplexes with the uranyl: polyphosphate ratio, equalling 1:2, are shown to be formed at pH 4.5-8.2. Stability of complexes in the trimeta- < tetrameta- < hexametaphosphate series increases, and in the ortho- > pyro- > tripolyphosphate series decreases. Correlation dependence of stability constants of studied uranium (6) polyphosphate complexes on acid properties of ligands coordinated by the uranyl group is establised