The preparation and structural characterization of 1-methylimidazolium and 1,3-dimethylimidazolium tetrachlorobismuthate(III)

Abstract

In attempting to synthesize complexes of BiCl₃ with 1-methyl-2(3H)-imidazolethione and 1,3-dimethyl-2(3H)-imidazoletellurone, the respective imidazolium salts stabilized by the tetrachlorobismuthate(III) anion were obtained. The two new compounds are characterized via standard methods and X-ray crystallography. One compound, 1,3-dimethylimidazolium tetrachlorobismuthate(III), crystallizes in space group C2/c with a = 14.7000(12), b = 12.7200(8), c = 7.3150(6) Å, and β = 117.744(5)^○. The other compound, 1-methylimidazolium tetrachlorobismuthate(III), crystallizes in space group P2₁/c with a = 11.1534(12), b = 12.9635(14), c = 7.2856(8) Å, and β = 94.319(2)^○. The large anion is comprised of polymeric zig-zag chains of octahedrally coordinated bismuth sharing alternating edges through cis chlorine bridging. The resulting long linear channels house the planar cations stacked parallel to each other. Differences in anion geometries can be attributed to hydrogen bonding in the 1-methyl imidazolium salt, and there is no strong evidence of lone-pair stereoactivity in either of the compounds.