3,9-Bis(dicyanomethylene)-2,4,8,10-tetrathiaspiro[5.5]undecane

The title compound, 2,2'-(2,4,8,10-tetrathiaspiro[5.5]undecane-3,9-diyliden e)bis(propanedinitrile), C13H8N4S4, has been designed and synthesized for u se as a potential new organic molecular electronic material. The spiro-annu lated structure has twofold symmetry and is formed by two equal push-pull e thylene units, with the cycloalkylthio groups as electron donors and the cy ano groups as electron acceptors. The intermolecular S . . .N non-bonded se paration within a layer in the lattice is 3.296 (6) Angstrom, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring molecules have a shortest S . . .S c ontact of 3.449 (3) Angstrom. In addition, attractive C-H . . .N and C-H . . .S interactions bridge adjacent molecules either within a layer or betwee n layers. In short, these four types of intermolecular interactions combine to form an extended three-dimensional network in the lattice, resulting in a highly ordered array of molecular packing.