K2C7NH2O5Cl crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 5-coordinate geometry to one O(5), two equivalent O(2), and two equivalent O(4) atoms. The K(1)-O(5) bond length is 2.69 Å. There is one shorter (2.70 Å) and one longer (2.78 Å) K(1)-O(2) bond length. There is one shorter (2.74 Å) and one longer (2.96 Å) K(1)-O(4) bond length. In the second K site, K(2) is bonded in a 6-coordinate geometry to one N(1), one O(1), one O(4), one O(5), and two equivalent O(3) atoms. The K(2)-N(1) bond length is 2.83 Å. The K(2)-O(1) bond length is 2.81 Å. The K(2)-O(4) bond length is 2.89 Å. The K(2)-O(5) bond length is 2.73 Å. There is one shorter (2.74 Å) and one longer (3.08 Å) K(2)-O(3) bond length. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(6) and one O(1) atom. The C(1)-C(6) bond length is 1.43 Å. The C(1)-O(1) bond length is 1.25 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(3) and one O(2) atom. The C(2)-C(3) bond length is 1.41 Å. The C(2)-O(2) bond length is 1.26 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one Cl(1) atom. The C(3)-C(4) bond length is 1.41 Å. The C(3)-Cl(1) bond length is 1.73 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3) and one O(3) atom. The C(4)-O(3) bond length is 1.26 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(6) and one O(4) atom. The C(5)-C(6) bond length is 1.43 Å. The C(5)-O(4) bond length is 1.26 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(1), one C(5), and one C(7) atom. The C(6)-C(7) bond length is 1.41 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(6) and one N(1) atom. The C(7)-N(1) bond length is 1.17 Å. N(1) is bonded in a distorted single-bond geometry to one K(2) and one C(7) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), and one C(5) atom. In the second O site, O(5) is bonded in a distorted water-like geometry to one K(1), one K(2), one H(1), and one H(2) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one K(2) and one C(1) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one C(2) atom. In the fifth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(2) and one C(4) atom. Cl(1) is bonded in a single-bond geometry to one C(3) atom. Linkers: 2 O ,2 N#C[C]1C(=O)C(=O)[C](Cl)C(=O)C1=O. Metal clusters: 4 [K]. The MOF has largest included sphere 0.97 A, density 1.96 g/cm3, surface area 1105.32 m2/g, accessible volume 0.01 cm3/g