The Arsenic Oxide Trichloride Dimer

The crystal structure and Raman spectrum of AsOCl₃ reveals that in the solid state it consists of double oxygen bridged dimers with a trigonal bipyramidal structure environment around the arsenic atoms. (a = 804.3(2), b = 613.1(2), c = 1019.7(2) pm, β = 111.99(2)°, space group P2₁/c, Z = 4). In solution of CH₂Cl₂ it is monomeric, as evidenced by Raman spectroscopy. These findings are supported by ab initio and density functional calculations.