catena‐Poly[[(2,2′‐biimidazole‐κ2N,N′)chloro­copper(II)]‐μ‐chloro]

In the polymeric title compound, [CuCl₂(C₆H₆N₄)]_n, each Cu^II ion is five‐coordinated by four basal atoms (two N atoms from a 2,2′‐biimidazole mol­ecule and two Cl⁻ anions) and one axial Cl⁻ anion, in a distorted square‐pyramidal coordination geometry. Cl⁻ anions bridge the {Cu(C₆H₆N₄)Cl} units into one‐dimensional linear chains, which are reinforced by π–π inter­actions. Adjacent linear chains are linked by N—H⋯Cl hydrogen bonds, resulting in a grid layer. The hydrogen‐bonding pattern can be described in graph‐set notation as C(9)R(9)R(14). This study extends our knowledge of the multifunctional properties of the 2,2′‐biimidazole ligand and of the coordination stereochemistry of copper(II).