BaC9H4(NO2)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(8), two equivalent O(4), and two equivalent O(7) atoms. The Ba(1)-O(1) bond length is 2.88 Å. The Ba(1)-O(2) bond length is 2.92 Å. The Ba(1)-O(3) bond length is 2.76 Å. The Ba(1)-O(8) bond length is 2.65 Å. There is one shorter (2.68 Å) and one longer (2.76 Å) Ba(1)-O(4) bond length. There is one shorter (2.76 Å) and one longer (2.84 Å) Ba(1)-O(7) bond length. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(1), one O(3), one O(4), one O(7), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. The Ba(2)-O(1) bond length is 2.84 Å. The Ba(2)-O(3) bond length is 2.78 Å. The Ba(2)-O(4) bond length is 3.25 Å. The Ba(2)-O(7) bond length is 3.42 Å. There is one shorter (2.91 Å) and one longer (3.06 Å) Ba(2)-O(2) bond length. There is one shorter (2.69 Å) and one longer (3.05 Å) Ba(2)-O(5) bond length. There is one shorter (2.75 Å) and one longer (2.90 Å) Ba(2)-O(6) bond length. There are eighteen inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(6), and one O(8) atom. The C(1)-C(11) bond length is 1.50 Å. The C(1)-O(6) bond length is 1.29 Å. The C(1)-O(8) bond length is 1.26 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(17), one C(3), and one C(7) atom. The C(2)-C(17) bond length is 1.50 Å. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(7) bond length is 1.42 Å. In the third C site, C(3) is bonded in a distorted trigonal planar 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 1.09 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one N(1) atom. The C(4)-C(5) bond length is 1.42 Å. The C(4)-N(1) bond length is 1.38 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 N(2) atom. The C(5)-C(6) bond length is 1.40 Å. The C(5)-N(2) bond length is 1.39 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(5), one C(7), and one H(2) atom. The C(6)-C(7) bond length is 1.40 Å. The C(6)-H(2) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(18), one C(2), and one C(6) atom. The C(7)-C(18) bond length is 1.50 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(4) atom. The C(8)-N(1) bond length is 1.36 Å. The C(8)-N(2) bond length is 1.33 Å. The C(8)-H(4) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(10), one C(14), and one H(5) atom. The C(9)-C(10) bond length is 1.40 Å. The C(9)-C(14) bond length is 1.40 Å. The C(9)-H(5) bond length is 1.09 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(11), one C(16), and one C(9) atom. The C(10)-C(11) bond length is 1.42 Å. The C(10)-C(16) bond length is 1.50 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(1), one C(10), and one C(12) atom. The C(11)-C(12) bond length is 1.40 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(11), one C(13), and one H(6) atom. The C(12)-C(13) bond length is 1.39 Å. The C(12)-H(6) bond length is 1.09 Å. In the thirteenth C site, C(13) is bonded in a distorted trigonal planar geometry to one C(12), one C(14), and one N(4) atom. The C(13)-C(14) bond length is 1.42 Å. The C(13)-N(4) bond length is 1.39 Å. In the fourteenth C site, C(14) is bonded in a distorted trigonal planar geometry to one C(13), one C(9), and one N(3) atom. The C(14)-N(3) bond length is 1.38 Å. In the fifteenth C site, C(15) is bonded in a trigonal planar geometry to one N(3), one N(4), and one H(8) atom. The C(15)-N(3) bond length is 1.36 Å. The C(15)-N(4) bond length is 1.33 Å. The C(15)-H(8) bond length is 1.09 Å. In the sixteenth C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(10), one O(1), and one O(2) atom. The C(16)-O(1) bond length is 1.28 Å. The C(16)-O(2) bond length is 1.27 Å. In the seventeenth C site, C(17) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(17)-O(3) bond length is 1.27 Å. The C(17)-O(4) bond length is 1.28 Å. In the eighteenth C site, C(18) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(5), and one O(7) atom. The C(18)-O(5) bond length is 1.27 Å. The C(18)-O(7) bond length is 1.29 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(4), one C(8), and one H(3) atom. The N(1)-H(3) bond length is 1.06 Å. In the second N site, N(2) is bonded in a 3-coordinate geometry to one C(5), one C(8), and one H(7) atom. The N(2)-H(7) bond length is 1.72 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one C(14), one C(15), and one H(7) atom. The N(3)-H(7) bond length is 1.06 Å. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one C(13), one C(15), and one H(3) atom. The N(4)-H(3) bond length is 1.70 Å. There are eight 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(6) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one N(1) and one N(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(8) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(9) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(12) atom. In the seventh H site, H(7) is bonded in a distorted single-bond geometry to one N(2) and one N(3) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(15) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(16) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Ba(1), two equivalent Ba(2), and one C(16) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(17) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(17) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(18) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(18) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Ba(1) and one C(1) atom. Linkers: 4 [O]C(=O)c1cc2nc[nH]c2cc1C([O])=O. Metal clusters: 4 [Ba]. The MOF has largest included sphere 2.28 A, density 2.42 g/cm3, surface area 2477.25 m2/g, accessible volume 0.06 cm3/g