The chemistry of uranium. Part 38. The interaction of UI 4 with sulphoxide ligands and the use of dimethyl sulphoxide as oxidizing agent in the preparation of UO 2I 2 complexes

Abstract

The reactions of UI 4 with a number of sulphoxide donor ligands have been studied in non-aqueous media and compared to the behaviour of UCl 4 and UBr 4 in the presence of these ligands. UI 4 is readily oxidized by dmso (dimethyl sulphoxide) and dibso (di-isobutyl sulphoxide) at room temperature and the only stable complexes isolated were UI 4(dmso) 8 and UI 4 (dibso) 6. The large tbso (di-tertiarybutyl sulphoxide) gives stable, bis-complexes, UX 4L 2 for all three halides. The oxidation of UI 4 by dmso in ethyl acetate provides a relatively easy and reliable method for the preparation of uranyl iodide complexes, e.g. UO 2I 4A 2 (A = Ph 4P +, Ph 4As +, etc.), UO 2I 2L 2 (L = triphenylarsine oxide (tpao), tris- (dimethylamino)phosphine oxide (tdpo), N, N′- dimethylpropylene urea (dmpu), N, N, N′, N′-tetra- methylurea (tmu) and N, N′-dimethylethylene urea (dmeu) and UO 2I 2L 4 where L = tdpo and tpao.