A uniform and one-dimensional stacking of 2,5-di­chloro­tetra­cyano­quinodimethanide mol­ecules in the tetra­methyl­arsonium salt

In the tetra­methyl­arsonium salt of 2,5-di­chloro-7,7,8,8-tetra­cyano­quinodimethanide [systematic name: tetra­methyl­arson­ium 2,2′-(2,5-dichlorocyclohexa-2,5-diene-1,4-diylidene)bis(propanedinitrile)], C₄H₁₂As⁺·C₁₂H₂Cl₂N₄⁻ or [As(CH₃)₄](C₁₂H₂Cl₂N₄), the cation lies disordered about a twofold axis and the radical ion lies about an inversion center forming a uniform [interplanar distance 3.35 (2) Å] and one-dimensional stacking without any slip. The electrical conductivity of the single crystal at room temperature was less than 10⁻⁹ S cm⁻¹, and the temperature dependence of para­magnetic susceptibility obeyed a one-dimensional antiferromagnetic Heisenberg model with a spin-exchange integral of 83 K in the temperature range 1.8–320.0 K.