Tricesium trans-tetraaquadichlorovanadium(III) tetrachloride: redetermination of the crystal structure and infrared study of the water spectrum

The discrepancy between the infrared data in the region of the O–D stretching vibrations and the proposed centrosymmetric space group Immm for tricesium trans-tetra-aquadichlorovanadium(III) tetrachloride, Cs3[VCl2(H2O)4]Cl4, was the reason behind our decision to redetermine the crystal structure of this compound and refine it in the non-centrosymmetric space group I222. Crystal data: Cs3VCl6$4H2O, orthorhombic, I222, aZ8.346(1), bZ17.646(2), cZ6.044(1) A ° , VZ890.1(2) A ° 3, ZZ2. The water molecules were found to occupy general positions, each of them forming two non-equivalent hydrogen bonds of the Ow/Cl type (3.032 and 3.043 A ° ). These structural data agree well with the appearance of two bands in the O–D stretching region of the infrared spectrum of the isotopically isolated HOD molecules. q 2004 Elsevier B.V. All rights reserved