Proton nuclear magnetic resonance studies of the 8-quinolinol complexes of thorium(IV) and uranium(VI)

Article abstract of DOI:10.1021/ic50075a027

The proton nmr spectra of the 8-quinolinol (oxine, HOx) complexes of thorium(IV) and uranium(VI) in DMSO solutions have been recorded and analyzed. The data establish that the solvated complexes of thorium and uranium, ThOx₄· HOx and UO₂Ox₂·HOx, only exist in the solid phase and dissociate to ThOx₄ and UO₂Ox₂ in solution. The oxines in the latter complexes are equivalent on the basis of the nmr data. Studies of the UO₂Ox₃^- complex also confirm that the three oxines are equivalent. Drying studies and differential thermograms of the various solvated oxine complexes of thorium and uranium have been used to characterize the solid species. The red form of UO₂Ox₂·HOx has a much greater thermal stability than the orange form and can be dried to constant weight at 150°. The maroon hydrate, UO₂Ox₂·3H₂O, also is stable up to 150°.