The crystal and molecular structure of dipyrrolidylthiuram disulfide

Abstract

The crystal structure of dipyrrolidylthiuram disulfide has been determined by single-crystal X-ray diffraction techniques at 295 K. Crystals are monoclinic, space group C2/c, unit cell a 13.835(3), b 10.422(2), c 9.427(3) Å, β 97.08(2)º and Z 4. Automatic diffractometry has provided significant Bragg intensities for 1402 independent reflections, and the structure has been refined by least-squares methods to R 0.037. The structure consists of discrete C₄H₈NC(S)S₂C(S)NC₄H₈ molecules. Half of each molecule is crystallographically unique with distances S-S 2.002(1), and C-S 1.804(2) and 1.645(2) Å. The dihedral angle between planar C₂NC(S)S portions is 87.9º. The relevance of the derived structural parameters to the question of why the tris(pyrrolidine-1-carbodithioato)iron(III) complex is, uniquely, high spin is discussed.