Synthetic, spectroscopic and structural studies on uranium and thorium complexes of diphosphazane dioxides

Abstract

Co-ordination complexes of the diphosphazane dioxides Ph₂P(O)N(Prⁱ)P(O)Ph₂ L¹, Ph₂P(O)N(Prⁱ)P(O)Ph(OC₆H₄Me-4) L² and Ph₂P(O)N(Prⁱ)P(O)(O₂C₁₂H₈) L³ with UO₂²⁺ or Th⁴⁺ ions have been synthesised and characterised by IR and NMR spectroscopy. The structures of [UO₂(NO₃)₂L¹] and [Th(NO₃)₂L¹₃][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 L¹; the co-ordination polyhedron around the metal is a hexagonal bipyramid. The cationic moiety in the thorium complex contains three bidentate diphosphazane dioxide ligands and two bidentate nitrate groups around the ten-co-ordinated metal.