KC3H3(N2O3)2 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 9-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(6), one O(7), one O(8), and two equivalent O(5) atoms. The K(1)-O(1) bond length is 2.88 Å. The K(1)-O(10) bond length is 3.03 Å. The K(1)-O(2) bond length is 2.95 Å. The K(1)-O(4) bond length is 2.73 Å. The K(1)-O(6) bond length is 2.71 Å. The K(1)-O(7) bond length is 3.04 Å. The K(1)-O(8) bond length is 2.91 Å. There is one shorter (2.79 Å) and one longer (2.98 Å) K(1)-O(5) bond length. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(12), one O(2), one O(3), one O(7), one O(8), one O(9), and two equivalent O(11) atoms. The K(2)-O(1) bond length is 3.04 Å. The K(2)-O(12) bond length is 2.71 Å. The K(2)-O(2) bond length is 2.91 Å. The K(2)-O(3) bond length is 3.03 Å. The K(2)-O(7) bond length is 2.88 Å. The K(2)-O(8) bond length is 2.95 Å. The K(2)-O(9) bond length is 2.73 Å. There is one shorter (2.79 Å) and one longer (2.97 Å) K(2)-O(11) bond length. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one N(1), and one N(2) atom. The C(1)-C(2) bond length is 1.48 Å. The C(1)-N(1) bond length is 1.40 Å. The C(1)-N(2) bond length is 1.41 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(1), one N(3), and one O(5) atom. The C(2)-N(3) bond length is 1.38 Å. The C(2)-O(5) bond length is 1.25 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(3), one N(4), and one O(6) atom. The C(3)-N(3) bond length is 1.41 Å. The C(3)-N(4) bond length is 1.33 Å. The C(3)-O(6) bond length is 1.25 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(5), one N(5), and one N(6) atom. The C(4)-C(5) bond length is 1.48 Å. The C(4)-N(5) bond length is 1.40 Å. The C(4)-N(6) bond length is 1.41 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(4), one N(7), and one O(11) atom. The C(5)-N(7) bond length is 1.38 Å. The C(5)-O(11) bond length is 1.25 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(7), one N(8), and one O(12) atom. The C(6)-N(7) bond length is 1.41 Å. The C(6)-N(8) bond length is 1.33 Å. The C(6)-O(12) bond length is 1.25 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(1), one O(1), and one O(2) atom. The N(1)-O(1) bond length is 1.26 Å. The N(1)-O(2) bond length is 1.26 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one C(1), one O(3), and one O(4) atom. The N(2)-O(3) bond length is 1.26 Å. The N(2)-O(4) bond length is 1.25 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one C(2); one C(3); and one H(1,4) atom. The N(3)-H(1,4) bond length is 1.02 Å. In the fourth N site, N(4) is bonded in a trigonal planar geometry to one C(3), one H(2), and one H(3) atom. The N(4)-H(2) bond length is 1.03 Å. The N(4)-H(3) bond length is 1.02 Å. In the fifth N site, N(5) is bonded in a trigonal planar geometry to one C(4), one O(7), and one O(8) atom. The N(5)-O(7) bond length is 1.26 Å. The N(5)-O(8) bond length is 1.26 Å. In the sixth N site, N(6) is bonded in a trigonal planar geometry to one C(4), one O(10), and one O(9) atom. The N(6)-O(10) bond length is 1.26 Å. The N(6)-O(9) bond length is 1.25 Å. In the seventh N site, N(7) is bonded in a trigonal planar geometry to one C(5); one C(6); and one H(1,4) atom. The N(7)-H(1,4) bond length is 1.02 Å. In the eighth N site, N(8) is bonded in a trigonal planar geometry to one C(6), one H(5), and one H(6) atom. The N(8)-H(5) bond length is 1.03 Å. The N(8)-H(6) bond length is 1.02 Å. There are five inequivalent H sites. In the first H site, H(1,4) is bonded in a single-bond geometry to one N(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one N(4) atom. In the fourth H site, H(5) is bonded in a single-bond geometry to one N(8) atom. In the fifth H site, H(6) is bonded in a single-bond geometry to one N(8) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one N(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one N(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one K(2) and one N(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1) and one N(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent K(1) and one C(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one K(1) and one C(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one N(5) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one N(5) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one K(2) and one N(6) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one K(1) and one N(6) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to two equivalent K(2) and one C(5) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one K(2) and one C(6) atom. Linkers: 4 NC(=O)NC(=O)[C]([N+](=O)[O-])[N+](=O)[O-]. Metal clusters: 4 [K]. The MOF has largest included sphere 1.36 A, density 2.02 g/cm3, surface area 1717.35 m2/g, accessible volume 0.02 cm3/g