Na2FeC18(O2Cl)6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted pentagonal pyramidal geometry to one O(1), one O(11), one O(12), one O(2), one O(7), and one O(8) atom. The Na(1)-O(1) bond length is 2.38 Å. The Na(1)-O(11) bond length is 2.35 Å. The Na(1)-O(12) bond length is 2.38 Å. The Na(1)-O(2) bond length is 2.31 Å. The Na(1)-O(7) bond length is 2.34 Å. The Na(1)-O(8) bond length is 2.54 Å. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(12), one O(2), one O(7), and one O(8) atom. The Na(2)-O(1) bond length is 2.53 Å. The Na(2)-O(12) bond length is 2.36 Å. The Na(2)-O(2) bond length is 2.45 Å. The Na(2)-O(7) bond length is 2.33 Å. The Na(2)-O(8) bond length is 2.69 Å. Fe(1) is bonded in an octahedral geometry to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom. The Fe(1)-O(10) bond length is 1.99 Å. The Fe(1)-O(3) bond length is 2.01 Å. The Fe(1)-O(4) bond length is 2.01 Å. The Fe(1)-O(5) bond length is 2.01 Å. The Fe(1)-O(6) bond length is 2.01 Å. The Fe(1)-O(9) bond length is 2.04 Å. There are eighteen inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one Cl(1) atom. The C(1)-C(2) bond length is 1.42 Å. The C(1)-C(6) bond length is 1.37 Å. The C(1)-Cl(1) bond length is 1.73 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1) and one O(1) atom. The C(2)-O(1) bond length is 1.24 Å. In the third C site, C(3) is bonded in a single-bond geometry to one C(4) and one O(2) atom. The C(3)-C(4) bond length is 1.42 Å. The C(3)-O(2) bond length is 1.24 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one Cl(2) atom. The C(4)-C(5) bond length is 1.38 Å. The C(4)-Cl(2) bond length is 1.73 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4) and one O(3) atom. The C(5)-O(3) bond length is 1.28 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1) and one O(4) atom. The C(6)-O(4) bond length is 1.28 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(12), one C(8), and one Cl(3) atom. The C(7)-C(12) bond length is 1.44 Å. The C(7)-C(8) bond length is 1.37 Å. The C(7)-Cl(3) bond length is 1.73 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(7) and one O(5) atom. The C(8)-O(5) bond length is 1.29 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(10) and one O(6) atom. The C(9)-C(10) bond length is 1.38 Å. The C(9)-O(6) bond length is 1.28 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(11), one C(9), and one Cl(4) atom. The C(10)-C(11) bond length is 1.42 Å. The C(10)-Cl(4) bond length is 1.73 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(10) and one O(7) atom. The C(11)-O(7) bond length is 1.24 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(7) and one O(8) atom. The C(12)-O(8) bond length is 1.23 Å. In the thirteenth C site, C(13) is bonded in a trigonal planar geometry to one C(14), one C(18), and one Cl(5) atom. The C(13)-C(14) bond length is 1.38 Å. The C(13)-C(18) bond length is 1.42 Å. The C(13)-Cl(5) bond length is 1.73 Å. In the fourteenth C site, C(14) is bonded in a distorted single-bond geometry to one C(13) and one O(9) atom. The C(14)-O(9) bond length is 1.28 Å. In the fifteenth C site, C(15) is bonded in a single-bond geometry to one C(16) and one O(10) atom. The C(15)-C(16) bond length is 1.37 Å. The C(15)-O(10) bond length is 1.28 Å. In the sixteenth C site, C(16) is bonded in a trigonal planar geometry to one C(15), one C(17), and one Cl(6) atom. The C(16)-C(17) bond length is 1.43 Å. The C(16)-Cl(6) bond length is 1.73 Å. In the seventeenth C site, C(17) is bonded in a distorted single-bond geometry to one C(16) and one O(11) atom. The C(17)-O(11) bond length is 1.23 Å. In the eighteenth C site, C(18) is bonded in a single-bond geometry to one C(13) and one O(12) atom. The C(18)-O(12) bond length is 1.24 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one C(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one C(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(5) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(8) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one C(11) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one C(12) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(14) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(15) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Na(1) and one C(17) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one C(18) atom. There are six inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a single-bond geometry to one C(1) atom. In the second Cl site, Cl(2) is bonded in a single-bond geometry to one C(4) atom. In the third Cl site, Cl(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth Cl site, Cl(4) is bonded in a single-bond geometry to one C(10) atom. In the fifth Cl site, Cl(5) is bonded in a single-bond geometry to one C(13) atom. In the sixth Cl site, Cl(6) is bonded in a single-bond geometry to one C(16) atom. Linkers: 4 [O]C1=C(Cl)C(=O)C(=O)[C](Cl)C1=O. Metal clusters: 8 [Na] ,4 [Fe]. The MOF has largest included sphere 5.83 A, density 1.36 g/cm3, surface area 3236.51 m2/g, accessible volume 0.31 cm3/g