A new monoclinic polymorph of 1,1′-bis­(di­phenyl­thio­phosphor­yl)ferrocene

The title compound, [Fe(C(17)H(14)PS)(2)], is a second monoclinic polymorph (P2(1)/c, with Z′ = 1) of the previously reported monoclinic (C2/c, with Z′ = 1/2) form [Fang et al. (1995 ▸). Polyhedron, 14, 2403–2409]. In the new form, the S atoms lie to the same side of the mol­ecule with the pseudo S—P⋯P—S torsion angle being −53.09 (3)°. By contrast to this almost syn disposition, in the C2/c polymorph, the Fe atom lies on a centre of inversion so that the S atoms are strictly anti, with a pseudo-S—P⋯P—S torsion angle of 180°. The significant difference in mol­ecular conformation between the two forms does not result in major perturbations in the P=S bond lengths nor in the distorted tetra­hedral geometries about the P atoms. The crystal packing of the new monoclinic polymorph features weak Cp—C—H⋯π(phen­yl) inter­actions consolidating linear supra­molecular chains along the a axis. These pack with no directional inter­actions between them.