Multiple twinning in Co(C₁₅H₁₁OS)₃

Crystals of tris(3-mercapto-1,3-diphenyl-2-propen-1-onato)cobalt(III), Co(C₁₅H₁₁OS)₃, C₄₅H₃₃CoO₃S₃, are monoclinic, P2₁/a, a = 19.33, b = 11.02, c = 18.13 Å, all ±0.3%, β = 93°0′±15′; Dobs = 1.346 (5) Mg m⁻³ at 293 K giving Z = 4 and D_x = 1.338 Mg m⁻³. Multiple twinning results from fortuitous pseudo-orthorhombic and pseudo-hexagonal (a/b ≃√3) twin-lattice symmetry around c[001].