KC7H7(N2O)4 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to one N(2), one N(3), one N(5), one O(2), one O(3), one O(4), and two equivalent O(1) atoms. The K(1)-N(2) bond length is 3.13 Å. The K(1)-N(3) bond length is 2.88 Å. The K(1)-N(5) bond length is 2.89 Å. The K(1)-O(2) bond length is 2.82 Å. The K(1)-O(3) bond length is 3.00 Å. The K(1)-O(4) bond length is 2.92 Å. There is one shorter (2.85 Å) and one longer (3.14 Å) K(1)-O(1) bond length. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(5), and one H(1) atom. The C(1)-N(1) bond length is 1.38 Å. The C(1)-N(5) bond length is 1.31 Å. The C(1)-H(1) bond length is 1.08 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(2), and one N(3) atom. The C(2)-N(1) bond length is 1.40 Å. The C(2)-N(2) bond length is 1.34 Å. The C(2)-N(3) bond length is 1.33 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(2), one N(4), and one N(8) atom. The C(3)-N(2) bond length is 1.35 Å. The C(3)-N(4) bond length is 1.39 Å. The C(3)-N(8) bond length is 1.35 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one N(4) atom. The C(4)-C(5) bond length is 1.47 Å. The C(4)-N(1) bond length is 1.38 Å. The C(4)-N(4) bond length is 1.30 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one N(6), and one N(7) atom. The C(5)-N(6) bond length is 1.39 Å. The C(5)-N(7) bond length is 1.39 Å. In the sixth C site, C(6) is bonded to one N(8), one H(2), one H(3), and one H(4) atom to form corner-sharing CH3N tetrahedra. The C(6)-N(8) bond length is 1.45 Å. The C(6)-H(2) bond length is 1.09 Å. The C(6)-H(3) bond length is 1.10 Å. The C(6)-H(4) bond length is 1.10 Å. In the seventh C site, C(7) is bonded to one N(8), one H(5), one H(6), and one H(7) atom to form corner-sharing CH3N tetrahedra. The C(7)-N(8) bond length is 1.46 Å. The C(7)-H(5) bond length is 1.09 Å. The C(7)-H(6) bond length is 1.10 Å. The C(7)-H(7) bond length is 1.10 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 C(2), and one C(4) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one K(1), one C(2), and one C(3) atom. In the third N site, N(3) is bonded in a distorted single-bond geometry to one K(1), one C(2), and one N(5) atom. The N(3)-N(5) bond length is 1.38 Å. In the fourth N site, N(4) is bonded in a bent 120 degrees geometry to one C(3) and one C(4) atom. In the fifth N site, N(5) is bonded in a distorted single-bond geometry to one K(1), one C(1), and one N(3) atom. In the sixth N site, N(6) is bonded in a trigonal planar geometry to one C(5), one O(1), and one O(2) atom. The N(6)-O(1) bond length is 1.28 Å. The N(6)-O(2) 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 O(3), and one O(4) atom. The N(7)-O(3) bond length is 1.25 Å. The N(7)-O(4) bond length is 1.27 Å. In the eighth N site, N(8) is bonded in a trigonal planar geometry to one C(3), one C(6), and one C(7) atom. There are seven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(6) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(6) 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 single-bond geometry to one C(7) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(7) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(7) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1) and one N(6) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1) and one N(6) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one N(7) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1) and one N(7) atom. Linkers: 1 CN(C)C1=N[C]([C]([N+](=O)[O-])[N+](=O)[O-])N2C=N[N]C2=N1 ,2 O=N(=O)[C](C1=NC(=[N]=C2N1C=N[N]2)N(C)C)N(=O)=O ,1 CN(C)C1=N[C]([C]([N+](=O)[O-])[N+](=O)[O-])n2cnnc2[N]1. Metal clusters: 4 [K]. The MOF has largest included sphere 2.00 A, density 1.79 g/cm3, surface area 3025.89 m2/g, accessible volume 0.04 cm3/g