Synthesis, Characterization, Crystal Structure and hybrid DFT Computation

[NMe4 ]2 [As4 0 2 Clio] • 2 CH3CN was recovered by the reaction of [NMe4][N3] with AsCh in CH3CN under aerobic conditions. This compound was also obtained directly by the reaction of AsCb, AS2O3 and [NMe4][Cl] in acetonitrile. The structure was determined by X-ray diffraction. [NMe4 ]2 [As4 0 2Clio] • 2 CH3CN crystallizes in theoorthorhombic space group Fmmm with a = 11.4144(8), b = 14.732(1) and c = 19.803(2) A, with 4 formula units per unit cell. The frequencies obtained by Raman and infrared spectroscopy were assigned to the normal modes of the [As4 0 2 Cliol2~ anion in comparison with computational results. The bonding situation in the [As4 0 2 C1 io]‘~ anion was elucidated on the basis of an NBO analysis on the crystallographic data.