In the polymeric title compound, [Cu(im)Cl(phen)]n, where im is the imidazolate anion (C3H3N2) and phen is 1,10-phenanthroline (C12H8N2), each CuII ion is five-coordinated by four basal N atoms (two from two different im anions and two from one phen ligand) and one axial Cl atom, in a distorted square-pyramidal coordination geometry. Moreover, each im anion bridges two identical {CuCl(phen)}+ cations through its two N atoms, resulting in a one-dimensional zigzag chain along the crystallographic a axis. In addition, pairs of adjacent chains are staggered by π-π interactions, generating a two-dimensional layer, and neighbouring layers are further linked by two different kinds of C-H…Cl interactions, producing a three-dimensional network. [ABSTRACT FROM AUTHOR]