Quinoline-2(1H)-thione, a structure with Z′= 8.

The title compound, C9H7NS, crystallizes as the thione tautomer with Z′ = 8 (four independent dimers with local inversion symmetry via two N—H…S=C hydrogen-bond systems). The dimers are arranged in chains parallel to [&1macr;10], each chain being crystallographically independent. These chains are associated into layers via stacking of ring systems. The Z′ value can be rationalized in terms of a factor 2 for dimer formation without crystallographic symmetry and an additional factor 4 for differing stacking environments. [ABSTRACT FROM AUTHOR]