The diselanylbis(1,3-dimethyl-1H-imidazol-3-ium) dication stabilized by the polymeric catena-pentachloridotricuprate(I) anion

In the title compound, catena-poly[diselanylbis(1,3-dimethyl-1H-imidazol-3-ium) [μ₃-chlorido-tetra-μ₂-chlorido-tricuprate(I)]], {(C₁₀H₁₆N₄Se₂)[Cu₃Cl₅]}_n, the diselenide dication is stabilized by catena-[Cu₃Cl₅]²⁻ anions which associate through strong Cu—Cl bonds [average length = 2.3525 (13) Å] to form polymeric chains. The polymeric [Cu₃Cl₅]²⁻ anion contains crystallographically imposed twofold rotation symmetry, with distorted trigonal-planar and tetrahedral geometries around the two symmetry-independent Cu atoms. Likewise, the Se—Se bond of the cation is centered on a twofold rotation axis.