Uranium triiodide

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Uranium triiodide
Kristallstruktur Plutonium(III)-bromid.png
CAS number 13775-18-3
Molecular formula UI3
Molar mass 618.74232 g/mol
Appearance black solid
Density 6.78 g/cm3[1]
Melting point 766 °C (1,411 °F; 1,039 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Uranium triiodide is an inorganic chemical compound consisting of the elements uranium and iodine. An iodide, it has the chemical formula UI3.


Uranium triiodide may be obtained from the direct reaction of its constituent elements:[2]

2 U + 3 I2 → 2 UI3


Uranium triiodide is a black solid that melts at 766 °C.[3] It crystallizes in the orthorhombic crystal system (plutonium tribromide-type) in the space group Ccmm with the lattice parameters a = 432.8 pm, b = 1401.1 pm, and c = 1000.5 pm and four formula units per unit cell.[1] Uranium triiodide is suitable as a Lewis acidic catalyst for various Diels-Alder reactions, which are carried out under mild conditions.[4]


  1. ^ a b J. H. Levy, J. C. Taylor, P. W. Wilson: "The Structure of Uranium(III) Triiodide by Neutron Diffraction", in: Acta Cryst. B, 1975, 31, S. 880–882 (doi:10.1107/S0567740875003986).
  2. ^ Georg Brauer (ed.): Handbuch der Präparativen Anorganischen Chemie. 3rd edition. Vol. 2, Enke, Stuttgart 1978, ISBN 3-432-87813-3, p. 1218.
  3. ^ Arnold F. Holleman, Nils Wiberg: Lehrbuch der Anorganischen Chemie, 102. Auflage, de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1, S. 1969.
  4. ^ Jacqueline Collin, Leonor Maria, Isabel Santos: "Uranium Iodides as Catalysts for Diels–Alder Reactions", in: Journal of Molecular Catalysis A: Chemical, 2000, 160 (2), pp. 263–267 (doi:10.1016/S1381-1169(00)00257-0).