catena-Poly[[[iodidocopper(I)]-{μ-N-[(pyridin-2-yl-κN)methyl­idene]pyridin-3-amine-κ(2) N (3):N (1)}] acetonitrile hemisolvate]

In the asymmetric unit of the title polymeric complex, {[CuI(C(11)H(9)N(3))]·0.5CH(3)CN}(n), there are two Cu(I) atoms, two N-[(pyridin-2-yl-κN)methyl­idene]pyridin-3-amine (PyPy) ligands and two I atoms. Both Cu(I) atoms have a distorted tetra­hedral geometry, each being coordinated by one I atom, two N atoms of one PyPy ligand and one N atom from an adjacent PyPy ligand. In the crystal, infinite helical chains of [Cu(2)(PyPy)(2)](n) are formed propagating along the b axis. These chains are linked via weak C—H⋯I hydrogen bonds and π–π stacking inter­actions [shortest centroid–centroid distance = 3.2727 (14) Å]. During the refinement, electron-density peaks were located that were believed to be highly disordered solvent mol­ecules (possibly acetonitrile). The SQUEEZE option in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155] indicated there were solvent cavities with a total volume of 196 Å(3) containing approximately 60 electrons per unit cell, which equated to one mol­ecule of acetonitrile per asymmetric unit.