Structural studies of group 5B-halide-dithio-ligand complexes. Part 2. Crystal structures of 1:1 adducts of bis(NN-diethyldithiocarbamato)iodoantimony(III) with chloroform and molecular iodine

Crystallization of [Sb(S₂CNEt₂)₂l] from chloroform gives an adduct [Sb(S₂CNEt₂)₂l]·CHCl₃. Single-crystal X-ray structure determination shows the complex to be comprised of a polymeric chain of the form -Sb(S₂CNEt₂)₂-I-Sb(S₂CNEt ₂)₂- with bridging iodine atoms linking Sb(S₂CNEt₂)₂ units; the chloroform molecule is strongly hydrogen bonded to the polymer via the iodine atoms. Crystals are orthorhombic, space group Pcab, with a = 19.237(8), b = 12.534(5), c = 19.535(7) Å, and Z = 8, with the polymer chain parallel to b. Crystallization from methylene chloride instead with excess of iodine yields an adduct [Sb(S₂CNEt₂)₂l]·(0.5l₂) _x, x ≤ 1. The unit-cell dimensions are a ca. 22.5, b ca. 10.0, c ca. 19.2 Å, Z = 8, and the space group Pbcn. Again the structure is a polymeric unit (similar to the above) running parallel to b with adjacent strands linked by l₂ molecules charge-transfer bonded at the iodide units. As the molecular iodine content of the complex rises, its sites become increasingly populated, bonding the polymer strands more compactly and decreasing the cell volume.