ZnC3H3(N2O)2 crystallizes in the orthorhombic Pbca space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 4-coordinate geometry to one N(1), one N(5), one N(6), and one O(2) atom. The Zn(1)-N(1) bond length is 2.02 Å. The Zn(1)-N(5) bond length is 2.05 Å. The Zn(1)-N(6) bond length is 1.99 Å. The Zn(1)-O(2) bond length is 2.01 Å. In the second Zn site, Zn(2) is bonded in a distorted trigonal bipyramidal geometry to one N(2), one N(3), one N(7), one O(3), and one O(4) atom. The Zn(2)-N(2) bond length is 2.02 Å. The Zn(2)-N(3) bond length is 2.00 Å. The Zn(2)-N(7) bond length is 2.07 Å. The Zn(2)-O(3) bond length is 2.26 Å. The Zn(2)-O(4) bond length is 2.10 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(3) bond length is 1.27 Å. In the second C site, C(2) is bonded in a bent 120 degrees geometry to one O(2) and one O(4) atom. The C(2)-O(2) bond length is 1.27 Å. The C(2)-O(4) bond length is 1.26 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(1), one N(3), and one N(4) atom. The C(3)-N(1) bond length is 1.37 Å. The C(3)-N(3) bond length is 1.34 Å. The C(3)-N(4) bond length is 1.36 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(1) atom. The C(4)-N(1) bond length is 1.36 Å. The C(4)-N(2) bond length is 1.32 Å. The C(4)-H(1) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one N(5), one N(7), and one N(8) atom. The C(5)-N(5) bond length is 1.35 Å. The C(5)-N(7) bond length is 1.37 Å. The C(5)-N(8) bond length is 1.35 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(6), one N(7), and one H(2) atom. The C(6)-N(6) bond length is 1.32 Å. The C(6)-N(7) bond length is 1.35 Å. The C(6)-H(2) bond length is 1.08 Å. There are eight inequivalent N sites. In the first N site, N(3) is bonded in a distorted trigonal planar geometry to one Zn(2), one C(3), and one N(2) atom. The N(3)-N(2) bond length is 1.38 Å. In the second N site, N(4) is bonded in a distorted trigonal non-coplanar geometry to one C(3), one H(3), and one H(4) atom. The N(4)-H(3) bond length is 1.02 Å. The N(4)-H(4) bond length is 1.03 Å. In the third N site, N(5) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(5), and one N(6) atom. The N(5)-N(6) bond length is 1.39 Å. In the fourth N site, N(6) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(6), and one N(5) atom. In the fifth N site, N(7) is bonded in a trigonal planar geometry to one Zn(2), one C(5), and one C(6) atom. In the sixth N site, N(8) is bonded in a trigonal planar geometry to one C(5), one H(5), and one H(6) atom. The N(8)-H(5) bond length is 1.02 Å. The N(8)-H(6) bond length is 1.02 Å. In the seventh N site, N(1) is bonded in a trigonal planar geometry to one Zn(1), one C(3), and one C(4) atom. In the eighth N site, N(2) is bonded in a distorted trigonal planar geometry to one Zn(2), one C(4), and one N(3) atom. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(4) 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 N(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(8) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one N(8) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(2) and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(2) and one C(2) atom. Linkers: 5 NC1=NN=C[N]1 ,7 NC1=[N]=CN=N1 ,8 [O]C(=O)C([O])=O ,1 NC1=N[N]C=N1. Metal clusters: 16 [Zn]. The MOF has largest included sphere 4.23 A, density 1.68 g/cm3, surface area 3249.47 m2/g, accessible volume 0.26 cm3/g