Crystal structure of Cs2[Th(NO3)6]

Abstract

Dicaesium hexanitratothorate(IV), Cs2[Th(NO3)6], was synthesized in the form of colourless crystals by reaction of thorium nitrate and caesium nitrate in aqueous solution. The Th atom is located on an inversion centre and is coordinated by six chelating nitrate anions. The resulting ThO12coordination polyhedron is best described as a slightly distorted icosahedron. The Cs atom also has a coordination number of 12, but its coordination polyhedron is considerably more distorted. The crystal packing can be derived from an hexagonal dense packing (hcp) of idealized spherical CsO12and ThO12units. The CsO12units form a distorted hcp arrangement and half of the octahedral sites are occupied by the ThO12units.