A new polymorphic form of the title compound, di-1,4-butanediylthiuram disulfide [1,1'-dithiodicarbonothiolylbis(pyrrolidine)], C₁₀H₁₆N₂S₄, has been determined in the triclinic system. There are two simultaneous reports on structure determinations of this compound in the monoclinic system [Ymen (1983). Acta Chem. Scand. Ser. B, 37, 707-713; Williams, Statham & White (1983). Aust. J. Chem. 36, 1371-1377]. The two forms show differences in the conformation of one of the two pyrrolidine rings of the molecule.

The crystal structure of ferrocinium tetrachloroantimonate, [Fe(C₅H₅)₂][SbCl₄], has been determined at 173 K. The cyclopentadiene rings in the ferrocinium cation are in an eclipsed conformation. The Sb atom is coordinated by six Cl ions in an irregular octahedral arrangement. Two Cl⁻ ions form halogen bridges with neighbouring Sb atoms, resulting in a polymeric chain of anions {the compound may be named catena-poly[ferrocinium (dichloroantimonate-di-μ-chloro)]}. The ferrocinium cations are stacked between these polymeric chains and form two-dimensional layers parallel to the bc plane.