Ferrocene-1-carbaldehyde 4-ethylthiosemicarbazone

The asymmetric unit of title compound, [Fe(C5H5)(C9H12N3S)], contains two crystallographically independent molecules, A and B. The two cyclopentadienyl (Cp) rings are parallel to each other in both molecules, forming dihedral angles of 2.3 (3) and 1.0 (3)°, respectively, and adopt an eclipsed conformation. The mean plane of the semicarbazone group is twisted slightly away from the attached Cp ring in both molecules, the dihedral angles between the mean plane and the Cp ring being 15.3 (2) and 10.8 (2)°. The ethyl group in molecule A is coplanar with the mean plane of the semicarbazone group [C—N—C—C torsion angle = −175.2 (4)°], whereas it is nearly perpendicular in molecule B [C—N—C—C torsion angle = 84.8 (6)°]. In the crystal structure, intermolecular N—H...S hydrogen bonds link the molecules into dimers. These dimers are further linked into chains via intermolecular C—H...S hydrogen bonds. The crystal studied was a non-merohedral twin with a refined ratio of the twin components of 0.265 (2):0.735 (2)