Co2C9N4H4O5 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted octahedral geometry to two equivalent N(1), one O(1), one O(2), one O(4), and one O(5) atom. Both Co(1)-N(1) bond lengths are 2.26 Å. The Co(1)-O(1) bond length is 2.20 Å. The Co(1)-O(2) bond length is 2.11 Å. The Co(1)-O(4) bond length is 2.00 Å. The Co(1)-O(5) bond length is 2.09 Å. In the second Co site, Co(2) is bonded in a square co-planar geometry to two equivalent N(2) and two equivalent O(5) atoms. Both Co(2)-N(2) bond lengths are 2.09 Å. Both Co(2)-O(5) bond lengths are 2.07 Å. There are nine inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(2) bond length is 1.25 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(7) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(7) bond length is 1.39 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(1) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(8) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-C(8) bond length is 1.51 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4), one C(6), and one H(2) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(2) bond length is 0.93 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(9) atom. The C(6)-C(7) bond length is 1.39 Å. The C(6)-C(9) bond length is 1.48 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(2), one C(6), and one H(3) atom. The C(7)-H(3) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.23 Å. The C(8)-O(4) bond length is 1.25 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(6) and two equivalent N(1) atoms. Both C(9)-N(1) bond lengths are 1.34 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Co(1), one C(9), and one N(2) atom. The N(1)-N(2) bond length is 1.34 Å. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Co(2), one N(1), and one N(2) atom. The N(2)-N(2) bond length is 1.29 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(5) atom. The H(4)-O(5) bond length is 0.75 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in an L-shaped geometry to one Co(1) and one C(1) atom. In the second O site, O(2) is bonded in an L-shaped geometry to one Co(1) and one C(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one C(8) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Co(1) and one C(8) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Co(1), two equivalent Co(2), and one H(4) atom. Linkers: 2 [O]C(=O)c1cc(C([O])=O)cc(C2=NN=N[N]2)c1. Metal clusters: 4 [Co]. The MOF has largest included sphere 5.22 A, density 1.49 g/cm3, surface area 3063.98 m2/g, accessible volume 0.23 cm3/g