SYNTHETIC, SPECTROSCOPIC AND STRUCTURAL STUDIES ON URANIUM AND THORIUM COMPLEXES OF DIPHOSPHAZANE DIOXIDES

Co-ordination complexes of the diphosphazane dioxides Ph(2)P(O)N(Pr-i) P(O)Ph(2) L(1). Ph(2)P(O)N(Pr-i)P(O)Ph(OC(6)H(4)Me-4) L(2) and Ph(2)P( O)N(Pr-i)P(O)(O2C12H8) L(3) with UO22+ or Th4+ ions have been synthesi sed and characterised by IR and NMR spectroscopy. The structures of [U O2(NO3)(2)L(1)] and [Th(NO3)(2)L(3)(1)][Th(NO3)(6)] are established by X-ray crystallography. In the former, the uranyl ion is bonded to two bidentate nitrate groups and the two phosphoryl groups of the ligand L(1); the co-ordination polyhedron around the metal is a hexagonal bip yramid. The cationic moiety in the thorium complex contains three bide ntate diphosphazane dioxide ligands and two bidentate nitrate groups a round the ten-co-ordinated metal.