EuC18H9(NO2)3 crystallizes in the triclinic P-1 space group. Eu(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Eu(1)-O(1) bond length is 2.30 Å. The Eu(1)-O(2) bond length is 2.38 Å. The Eu(1)-O(3) bond length is 2.37 Å. The Eu(1)-O(4) bond length is 2.38 Å. The Eu(1)-O(5) bond length is 2.37 Å. The Eu(1)-O(6) bond length is 2.34 Å. 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(3), one O(1), and one O(5) atom. The C(1)-C(3) bond length is 1.51 Å. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(5) bond length is 1.24 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(11), one C(4), and one C(6) atom. The C(2)-C(11) bond length is 1.38 Å. The C(2)-C(4) bond length is 1.39 Å. The C(2)-C(6) bond length is 1.49 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(16), and one C(5) atom. The C(3)-C(16) bond length is 1.38 Å. The C(3)-C(5) bond length is 1.38 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(2), one C(7), and one H(1) atom. The C(4)-C(7) bond length is 1.38 Å. The C(4)-H(1) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(12), one C(3), and one H(2) atom. The C(5)-C(12) 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 distorted bent 120 degrees geometry to one C(2), one O(2), and one O(4) atom. The C(6)-O(2) bond length is 1.26 Å. The C(6)-O(4) bond length is 1.26 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(4), one C(7), and one N(3) atom. The C(7)-C(7) bond length is 1.49 Å. The C(7)-N(3) bond length is 1.35 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(14), one C(15), and one C(9) atom. The C(8)-C(14) bond length is 1.50 Å. The C(8)-C(15) bond length is 1.38 Å. The C(8)-C(9) bond length is 1.39 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(13), one C(8), and one H(3) atom. The C(9)-C(13) bond length is 1.39 Å. The C(9)-H(3) bond length is 0.93 Å. In the tenth C site, C(10) is bonded in a distorted trigonal planar geometry to one C(11), one N(3), and one H(4) atom. The C(10)-C(11) bond length is 1.38 Å. The C(10)-N(3) bond length is 1.33 Å. The C(10)-H(4) bond length is 0.93 Å. In the eleventh C site, C(11) is bonded in a single-bond geometry to one C(10), one C(2), and one H(5) atom. The C(11)-H(5) bond length is 0.93 Å. In the twelfth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(13), one C(5), and one N(1) atom. The C(12)-C(13) bond length is 1.48 Å. The C(12)-N(1) bond length is 1.34 Å. In the thirteenth C site, C(13) is bonded in a distorted single-bond geometry to one C(12), one C(9), and one N(2) atom. The C(13)-N(2) bond length is 1.34 Å. In the fourteenth C site, C(14) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(3), and one O(6) atom. The C(14)-O(3) bond length is 1.26 Å. The C(14)-O(6) bond length is 1.26 Å. In the fifteenth C site, C(15) is bonded in a distorted single-bond geometry to one C(8) and one H(6) atom. The C(15)-H(6) bond length is 0.93 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(18), one C(3), and one H(7) atom. The C(16)-C(18) bond length is 1.38 Å. The C(16)-H(7) bond length is 0.93 Å. In the seventeenth C site, C(17) is bonded in a distorted bent 120 degrees geometry to one N(2) and one H(8) atom. The C(17)-N(2) bond length is 1.34 Å. The C(17)-H(8) bond length is 0.93 Å. In the eighteenth C site, C(18) is bonded in a distorted trigonal planar geometry to one C(16), one N(1), and one H(9) atom. The C(18)-N(1) bond length is 1.34 Å. The C(18)-H(9) bond length is 0.93 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a bent 120 degrees geometry to one C(12) and one C(18) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one C(13) and one C(17) atom. In the third N site, N(3) is bonded in a bent 120 degrees geometry to one C(10) and one C(7) atom. There are nine 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(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(9) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(10) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(11) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(15) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(16) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(17) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(18) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Eu(1) and one C(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Eu(1) and one C(6) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Eu(1) and one C(14) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Eu(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Eu(1) and one C(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Eu(1) and one C(14) atom. Linkers: 3 [O]C(=O)c1ccnc(-c2cc(C([O])=O)ccn2)c1. Metal clusters: 2 [Eu]. The MOF has largest included sphere 5.04 A, density 1.52 g/cm3, surface area 3467.48 m2/g, accessible volume 0.28 cm3/g