Magnetic properties and structure of hexakisureavanadium tri-iodide

Abstract

The magnetic susceptibility and magnetic anisotropy of V(urea)₆I₃ was measured in the temperature range 80–300 K. The results were interpreted in terms of the ³T_1g ground term with the set of parameters λ= 45 cm^–1, Δ= 450 cm^–1, k= 0·5. The structure of the salt was determined by X-ray means at room temperature and at ca. 90 K. It changes only by a small anisotropic contraction of bond lengths. There is an appreciable distortion of the VO₆ octahedron by a ‘twist’ about a three-fold axis, which is not changed by temperature. There is also a very slight distortion of the octahedron along this axis, which changes from zero of a very slight compression at room temperature to a slight elongation at the low temperature.