CuC2PO3 crystallizes in the monoclinic C2/m space group. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 1.96 Å. Both Cu(1)-O(2) bond lengths are 2.05 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(2) and one P(1) atom. The C(1)-C(2) bond length is 1.54 Å. The C(1)-P(1) bond length is 1.80 Å. In the second C site, C(2) is bonded in a bent 120 degrees geometry to one C(1) and one C(2) atom. The C(2)-C(2) bond length is 1.59 Å. P(1) is bonded in a tetrahedral geometry to one C(1), one O(2), and two equivalent O(1) atoms. The P(1)-O(2) bond length is 1.56 Å. Both P(1)-O(1) bond lengths are 1.53 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Cu(1) and one P(1) atom. Linkers: 2 [O]P([O])(=O)[C]/[C]=[C]/[C]P([O])([O])=O. Metal clusters: 4 [Cu]. The MOF has largest included sphere 4.48 A, density 1.88 g/cm3, surface area 2933.10 m2/g, accessible volume 0.23 cm3/g