A triclinic modification of 5,5′-dinitro-2,2′-dithio­dipyridine

The asymmetric unit of the title compound, C(10)H(6)N(4)O(4)S(2), contains two independent but similar mol­ecules. The structure is a triclinic polymorph of the monoclinic structure reported previously [Brito, Mundaca, Cárdenas, López-Rodríguez & Vargas (2007 ▶). Acta Cryst. E63, o3351–o3352]. The most obvious difference between the two polymorphs is the C—S—S—C torsion angle [−80.13 (16), −79.8 (2) and 0° for the two mol­ecules of the triclinic polymorph and the monoclinic polymorph, respectively]. The crystal structure of the title compound has two intra­molecular C—H⋯S inter­actions with average H⋯S distances of 2.69 Å, whereas this kind of inter­action is not evident in the monoclinic polymorph.