Preparation, crystallographic properties, and infrared spectra of quadrivalent oxyhalides of thorium, protactinium, uranium, and neptunium

Abstract

Actinide(IV) oxydihalides of the type MOX₂(M = Th, Pa, U, and Np; X = Cl, Br, and I) have been prepared by reaction of the appropriate tetrahalide with antimony sesquioxide, Sb₂O₃, at 400° in a vaccum. Unit cell parameters are reported for the isostructural series of oxydichlorides which possess orthorhombic symmetry, space-group Pbam. Infrared spectra have been recorded for all the compounds and the results are compared with previous assignments for UOCl₂. Metal–oxygen vibrations occur in the region 600–225 cm.^–1.