CsC7H5SO6 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 10-coordinate geometry to one H(5), one O(2), two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. The Cs(1)-H(5) bond length is 3.31 Å. The Cs(1)-O(2) bond length is 2.99 Å. There is one shorter (3.42 Å) and one longer (3.48 Å) Cs(1)-O(1) bond length. There is one shorter (3.29 Å) and one longer (3.44 Å) Cs(1)-O(3) bond length. There is one shorter (2.99 Å) and one longer (3.16 Å) Cs(1)-O(4) bond length. There is one shorter (3.21 Å) and one longer (3.23 Å) Cs(1)-O(6) bond length. 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 C(7) atom. The C(1)-C(2) bond length is 1.42 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-C(7) bond length is 1.47 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 O(1) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-O(1) bond length is 1.35 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(2) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(2) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one H(3) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-H(3) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one S(1) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-S(1) bond length is 1.78 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(4) atom. The C(6)-H(4) 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(1), one O(5), and one O(6) atom. The C(7)-O(5) bond length is 1.32 Å. The C(7)-O(6) bond length is 1.26 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a distorted bent 150 degrees geometry to one O(1) and one O(6) atom. The H(1)-O(1) bond length is 1.01 Å. The H(1)-O(6) bond length is 1.63 Å. In the second H site, H(2) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(5) is bonded in a distorted linear geometry to one Cs(1), one O(3), and one O(5) atom. The H(5)-O(3) bond length is 1.55 Å. The H(5)-O(5) bond length is 1.03 Å. S(1) is bonded in a distorted trigonal non-coplanar geometry to one C(5), one O(2), one O(3), and one O(4) atom. The S(1)-O(2) bond length is 1.46 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.47 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to two equivalent Cs(1), one C(2), and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cs(1) and one S(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Cs(1), one H(5), and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Cs(1) and one S(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one C(7) and one H(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one C(7), and one H(1) atom. Linkers: 4 [O]S([O])([O])c1ccc(O)c(C(=O)O)c1. Metal clusters: 4 [Cs]. The MOF has largest included sphere 2.23 A, density 2.31 g/cm3, surface area 3172.05 m2/g, accessible volume 0.07 cm3/g