A one-dimensional copper(II) phenyl­ene­diphospho­nate: catena-poly[[(1,10-phenanthroline-κ(2) N,N′)copper(II)]-μ(3)-[m-phenyl­enediphospho­nato-κ(3) O:O′:O′′]]

The title compound, [Cu(1,3-HO(3)PC(6)H(4)PO(3)H)(C(12)H(8)N(2))](n), is a coordination polymer of the metal–diphospho­nate family. The chain structure is constructed from ‘4+1’ square-py­rami­dally coordinated copper(II) atoms bonded to chelating phenanthroline (phen) ligands and linked through 1,3-phenyldihydrogendiphospho­nate ligands. The basal plane of the Cu(II) site is defined by the phen nitro­gen donors and phospho­nate oxygen atoms from two diphospho­nate ligands, while the apical position is occupied by an oxygen donor from a third diphospho­nate ligand. The chains propagate along the a-axis direction. Inversion-related phen groups engage in π-π stacking with a mean distance of 3.376 (2) Å between the ring planes. O—H⋯O hydrogen-bonding inter­actions between the protonated {P—OH} groups of one chain and the {P=O} groups of adjacent chains stabilize the crystal packing.