Structural studies of group 5B–halide–dithio-ligand complexes. Part 5. Crystal structures of pentanuclear [Bi5(S2CNEt2)8X7], X = Cl, Br, or I, and the pyridinium salt of the tetranuclear [Bi4(S2CNEt2)4Br10]2– anion

Abstract

Recrystallization of the complexes [Bi(S₂CNEt₂)X₂], X = Cl, Br, or I, from dimethylformamide–n-butanol results in the formation of [Bi₅(S₂CNEt₂)₈X₇]·.dmf (dmf = dimethylformamide). The three complexes are isomorphous and have been characterized structurally by single-crystal X-ray diffraction, showing the structure to be comprised of a [BiX₆]^3– species acting as a central bridging unit by co-ordinating to four surrounding [Bi(S₂CNEt₂)₂]⁺ species, with an additional halide bridge preserving electroneutrality. The overall unit has crystallographically imposed 2 symmetry; the unit cell is monoclinic, space group C2/c, with a ca. 19.5, b ca. 20.5, c ca 21.5 Å, and βca. 102.5°. Recrystallization of [Bi(S₂NCEt₂)Br₂] from pyridine–n-butanol results in the formation of [NC₅H₆]₂[Bi₄(S₂CNEt₂)₄Br₁₀](solvated). The complex anion has a crystallographically imposed two-fold symmetry element.