CoC4N3H5O2 crystallizes in the tetragonal I4_1/a space group. Co(1) is bonded in a 6-coordinate geometry to one N(1), one N(2), one N(3), one H(5), one O(1), and one O(2) atom. The Co(1)-N(1) bond length is 2.06 Å. The Co(1)-N(2) bond length is 2.07 Å. The Co(1)-N(3) bond length is 2.05 Å. The Co(1)-H(5) bond length is 2.17 Å. The Co(1)-O(1) bond length is 2.29 Å. The Co(1)-O(2) bond length is 2.26 Å. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(3), one N(1), and one N(2) atom. The C(1)-C(3) bond length is 1.50 Å. The C(1)-N(1) bond length is 1.35 Å. The C(1)-N(2) bond length is 1.32 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one N(3) atom. The C(2)-C(4) bond length is 1.49 Å. The C(2)-N(1) bond length is 1.36 Å. The C(2)-N(3) bond length is 1.32 Å. In the third C site, C(3) is bonded in a distorted trigonal non-coplanar geometry to one C(1); two equivalent H(1,2); and one O(1) atom. Both C(3)-H(1,2) bond lengths are 0.97 Å. The C(3)-O(1) bond length is 1.41 Å. In the fourth C site, C(4) is bonded in a distorted trigonal non-coplanar geometry to one C(2), one H(3), one H(4), and one O(2) atom. The C(4)-H(3) bond length is 0.97 Å. The C(4)-H(4) bond length is 0.97 Å. The C(4)-O(2) bond length is 1.41 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Co(1), one C(1), and one C(2) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Co(1), one C(1), and one N(3) atom. The N(2)-N(3) bond length is 1.39 Å. In the third N site, N(3) is bonded in a 3-coordinate geometry to one Co(1), one C(2), and one N(2) atom. There are four inequivalent H sites. In the first H site, H(1,2) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(4) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(5) is bonded in a single-bond geometry to one Co(1) and one O(1) atom. The H(5)-O(1) bond length is 0.84 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Co(1), one C(3), and one H(5) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Co(1) and one C(4) atom. Linkers: 2 [O]CC1=NC(CO)=N[N]1 ,3 [O]CC1=[N]=C(N=N1)CO ,3 [O]CC1=N[N]C(CO)=N1. Metal clusters: 8 [Co]. The MOF has largest included sphere 7.73 A, density 1.00 g/cm3, surface area 3509.51 m2/g, accessible volume 0.64 cm3/g