CoPHO5 crystallizes in the tetragonal I-42m space group. Co(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Co(1)-O(3) bond length is 1.96 Å. Both Co(1)-O(1) bond lengths are 1.93 Å. Both Co(1)-O(2) bond lengths are 2.00 Å. P(1) is bonded in a 6-coordinate geometry to one H(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms. The P(1)-H(1) bond length is 1.48 Å. The P(1)-O(3) bond length is 1.54 Å. Both P(1)-O(1) bond lengths are 1.49 Å. Both P(1)-O(2) bond lengths are 1.53 Å. H(1) is bonded in a 2-coordinate geometry to one P(1) and two equivalent O(2) atoms. Both H(1)-O(2) bond lengths are 1.08 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Co(1), one P(1), one H(1), and one O(2) atom. The O(2)-O(2) bond length is 0.75 Å. Linkers: 3 [O]P([O])(=O)OO ,1 [O]O.[O]P([O])[O] ,1 [O].[O]O.[O][P][O] ,3 O=P(=O)OO.[O]. Metal clusters: 8 [Co]. The MOF has largest included sphere 4.37 A, density 2.28 g/cm3, surface area 1775.97 m2/g, accessible volume 0.18 cm3/g