Poly[(μ-5,7-di-hydro-1,3-dithieno[3,4-:3',4'-]pyrazine-κ :'::')tetra-μ-iodido-tetra-copper]: a three-dimensional copper(I) coordination polymer.

The reaction of ligand 5,7-di-hydro-1,3-dithieno[3,4-:3',4'-]pyrazine () with CuI lead to the formation of a three-dimensional coordination polymer, incorporating the well known [Cu I ] staircase motif ( = 4). These polymer [CuI] chains are linked the N and S atoms of the ligand to form the three-dimensional coordination polymer poly[(μ-5,7-di-hydro-1,3-dithieno[3,4-:3',4'-]pyrazine-κ :'::')tetra-μ-iodido-tetra-copper], [CuI(CHNS)] (). The asymmetric unit is composed of half a ligand mol-ecule, with the pyrazine ring located about a center of symmetry, and two independent copper(I) atoms and two independent I ions forming the staircase motif centers of inversion symmetry. The framework is consolidated by C-H⋯I hydrogen bonds.