Poly[[[μ--1,2-bis-(pyridin-4-yl)ethene-κ :']-μ-iodido-copper(I)]--1,2-bis-(pyridin-4-yl)ethene (1/0.25)].

The title compound, {[CuI(bpe)]·0.25(bpe)} , was synthesized similarly to (CuI)(bpe) [Neal (2019 ▸). , , x190122] with red crystals grown from aceto-nitrile solutions of CuI and the bpe ligand [bpe = 1,2-bis-(pyridin-4-yl)ethene, CHN]. The structure of the title compound is a type 1 complex in the Graham nomenclature [Graham (2000 ▸). . , 5121-5132], having rhombic dimers of CuI that are bridged by two bpe ligands, to form oligomeric ribbons arranged as stairsteps. The step height is 2.8072 (11) Å, which is the Cu-I distance of the dimer [symmetry code (i): 1 - , 2 - , 1 - ]. The resulting polymer displays a two-dimensional honeycomb framework along the (01) plane, and disordered free bpe mol-ecules fill the voids in the crystal.