1-[2-(Pyrazin-2-ylsulfan-yl)eth-yl]pyrazine-2(1H)-thione.

The title multifunctional twisted organic ligand, C(10)H(10)N(4)S(2), contains a short C=S bond [1.671 (2) Å]. The dihedral angle between the two pyrazine rings is 39.