Wydział Chemii

A. Mech

Mirosław Karbowiak

Tadeusz Lis

Janusz Drożdżyński

2006

Polyhedron

25

2083-2092

10.1016/j.poly.2006.01.004

Naukowa

Angielski

Artykuł

Three different uranium trichloride hydrates of the formulas UCl₃ · 2H₂O · 2CH₃CN, UCl₃ · 6H₂O and UCl₃ · 7H₂O have been isolated from methylcyanide solutions of UCl₄, with a 1–5% water content, by reduction with liquid zinc amalgam. The crystal and molecular structures of the hydrates have been determined by X-ray single crystal analysis. UCl₃ · 2H₂O · 2CH₃CN crystallizes in the triclinic system (space group ) forming infinite zigzag chains in the [0 1 0] direction. The coordination polyhedron of the uranium atom is a bicapped trigonal prism, formed by two oxygen atoms of the water molecules, four bridging chlorine atoms, one terminal chlorine atom and one nitrogen atom of the methylcyanide molecule. UCl₃ · 6H₂O crystallizes in the monoclinic system (space group P2/n), with a monomeric structure. The uranium ion is eight-coordinated by two chlorine atoms and six oxygen atoms of the water molecules, which form a distorted square antiprism. UCl₃ · 7H₂O crystallizes in the triclinic system in the space group . The characteristic feature of this structure are [(H₂O)₇UCl₂U(H₂O)₇]⁴⁺ dimers. The coordination polyhedra, in the form of a tricapped trigonal prism, are linked through the complex network of the hydrogen bonds. UCl₃ · 6H₂O and UCl₃ · 7H₂O are isostructural with their lanthanide analogues.

https://doi.org/10.1016/j.poly.2006.01.004

http://www.elsevier.com