Sr(HOOCC6H4PO3H)2 crystallizes in the monoclinic C2/c space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Both Sr(1)-O(1) bond lengths are 2.62 Å. Both Sr(1)-O(3) bond lengths are 2.65 Å. There are two shorter (2.52 Å) and two longer (2.62 Å) Sr(1)-O(2) bond lengths. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one P(1) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-C(6) bond length is 1.41 Å. The C(1)-P(1) bond length is 1.80 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(3) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(3) bond length is 1.09 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(4) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(4) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(7) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-C(7) bond length is 1.49 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4) and one H(5) atom. The C(5)-H(5) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1) and one H(6) atom. The C(6)-H(6) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(4), and one O(5) atom. The C(7)-O(4) bond length is 1.25 Å. The C(7)-O(5) bond length is 1.32 Å. P(1) is bonded in a tetrahedral geometry to one C(1), one O(1), one O(2), and one O(3) atom. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.60 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(1) and one O(3) atom. The H(1)-O(1) bond length is 1.46 Å. The H(1)-O(3) bond length is 1.04 Å. In the second H site, H(2) is bonded in a linear geometry to one O(4) and one O(5) atom. The H(2)-O(4) bond length is 1.54 Å. The H(2)-O(5) bond length is 1.04 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(3) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(5) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(6) atom. There are five inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one C(7) and one H(2) atom. In the second O site, O(5) is bonded in a water-like geometry to one C(7) and one H(2) atom. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one P(1), and one H(1) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(1) atom. In the fifth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one P(1), and one H(1) atom. Linkers: 4 [O]P(=O)(O)c1ccc(C(=O)O)cc1. Metal clusters: 2 [Sr]. The MOF has largest included sphere 1.60 A, density 1.98 g/cm3, surface area 3529.16 m2/g, accessible volume 0.10 cm3/g