Structural studies of group 5B-halide-dithio-ligand complexes. Part 1. Crystal structures of bis(NN-diethyldithiocarbamato)-iodo- and -bromo-bismuth(III)

The crystal structures of the two compounds [Bi(S₂CNEt₂)₂l], (1), and [Bi(S₂CNEt₂)₂Br], (2), have been determined by single-crystal X-ray diffraction methods at 295(1) K and refined by least-squares procedures to conventional residuals of 0.044 and 0.040 respectively for 1 859 and 3 055 'observed' reflections. Crystals of (1) are monoclinic, space group P2₁/c, with a = 12.054(2), b = 18.444(3), c = 8.815(2) Å, β = 108.09(1)°, and Z = 4. The structure is a linear polymer with bridging iodine atoms cis in the co-ordination sphere of the six-co-ordinate bismuth [Bi-l, 3.257(2), 3.354(1) Å; Bi-S, 2.646(4)-2.860(5) Å]. Crystals of (2) are triclinic, space group P1, with a = 14.388(7), b = 14.033(5), c = 10.297(2) Å, α = 99.56(2), β = 104.70(3), γ = 108.10(3)°, and Z = 4. The structure comprises a tetranuclear centrosymmetric unit with the bismuth atoms bridged by two- and three-co-ordinate bromine atoms.