KH21(C3O2)7 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 5-coordinate geometry to one O(10), one O(20), one O(23), one O(3), and one O(5) atom. The K(1)-O(10) bond length is 2.66 Å. The K(1)-O(20) bond length is 2.70 Å. The K(1)-O(23) bond length is 2.68 Å. The K(1)-O(3) bond length is 2.89 Å. The K(1)-O(5) bond length is 2.76 Å. In the second K site, K(2) is bonded in a 5-coordinate geometry to one O(19), one O(24), one O(4), one O(6), and one O(9) atom. The K(2)-O(19) bond length is 2.70 Å. The K(2)-O(24) bond length is 2.68 Å. The K(2)-O(4) bond length is 2.89 Å. The K(2)-O(6) bond length is 2.76 Å. The K(2)-O(9) bond length is 2.67 Å. There are twenty-nine inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(13,14); one C(15,16); and one C(3) atom. The C(1)-C(13,14) bond length is 1.40 Å. The C(1)-C(15,16) bond length is 1.52 Å. The C(1)-C(3) bond length is 1.43 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(13,14); one C(15,16); and one C(4) atom. The C(2)-C(13,14) bond length is 1.40 Å. The C(2)-C(15,16) bond length is 1.52 Å. The C(2)-C(4) bond length is 1.43 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1); one C(19,20); and one C(5) atom. The C(3)-C(19,20) bond length is 1.45 Å. The C(3)-C(5) bond length is 1.44 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(19,20); one C(2); and one C(6) atom. The C(4)-C(19,20) bond length is 1.45 Å. The C(4)-C(6) bond length is 1.44 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(23), one C(3), and one C(7) atom. The C(5)-C(23) bond length is 1.51 Å. The C(5)-C(7) bond length is 1.37 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(24), one C(4), and one C(8) atom. The C(6)-C(24) bond length is 1.51 Å. The C(6)-C(8) bond length is 1.37 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(27,28); one C(5); and one C(9) atom. The C(7)-C(27,28) bond length is 1.46 Å. The C(7)-C(9) bond length is 1.49 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(10); one C(27,28); and one C(6) atom. The C(8)-C(10) bond length is 1.49 Å. The C(8)-C(27,28) bond length is 1.46 Å. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(11); one C(31,32); and one C(7) atom. The C(9)-C(11) bond length is 1.36 Å. The C(9)-C(31,32) bond length is 1.49 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(12); one C(31,32); and one C(8) atom. The C(10)-C(12) bond length is 1.36 Å. The C(10)-C(31,32) bond length is 1.49 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(13,14); one C(35); and one C(9) atom. The C(11)-C(13,14) bond length is 1.48 Å. The C(11)-C(35) bond length is 1.51 Å. In the twelfth C site, C(12) is bonded in a trigonal planar geometry to one C(10); one C(13,14); and one C(36) atom. The C(12)-C(13,14) bond length is 1.48 Å. The C(12)-C(36) bond length is 1.51 Å. In the thirteenth C site, C(13,14) is bonded in a trigonal planar geometry to one C(1); one C(11); and one C(39,40) atom. The C(13,14)-C(39,40) bond length is 1.47 Å. In the fourteenth C site, C(15,16) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(3) atom. The C(15,16)-O(1) bond length is 1.35 Å. The C(15,16)-O(3) bond length is 1.22 Å. In the fifteenth C site, C(17,18) is bonded in a tetrahedral geometry to one H(1,2); one H(3,4); one H(5,6); and one O(1) atom. The C(17,18)-H(1,2) bond length is 1.09 Å. The C(17,18)-H(3,4) bond length is 1.10 Å. The C(17,18)-H(5,6) bond length is 1.10 Å. The C(17,18)-O(1) bond length is 1.45 Å. In the sixteenth C site, C(19,20) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(5), and one O(7) atom. The C(19,20)-O(5) bond length is 1.24 Å. The C(19,20)-O(7) bond length is 1.36 Å. In the seventeenth C site, C(21,22) is bonded in a tetrahedral geometry to one H(11,12); one H(7,8); one H(9,10); and one O(7) atom. The C(21,22)-H(11,12) bond length is 1.10 Å. The C(21,22)-H(7,8) bond length is 1.09 Å. The C(21,22)-H(9,10) bond length is 1.10 Å. The C(21,22)-O(7) bond length is 1.45 Å. In the eighteenth C site, C(23) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(11), and one O(9) atom. The C(23)-O(11) bond length is 1.34 Å. The C(23)-O(9) bond length is 1.23 Å. In the nineteenth C site, C(24) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(10), and one O(12) atom. The C(24)-O(10) bond length is 1.23 Å. The C(24)-O(12) bond length is 1.34 Å. In the twentieth C site, C(25,26) is bonded in a tetrahedral geometry to one H(13), one H(15), one H(17), and one O(11) atom. The C(25,26)-H(13) bond length is 1.09 Å. The C(25,26)-H(15) bond length is 1.10 Å. The C(25,26)-H(17) bond length is 1.10 Å. The C(25,26)-O(11) bond length is 1.45 Å. In the twenty-first C site, C(27,28) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(13), and one O(15) atom. The C(27,28)-O(13) bond length is 1.24 Å. The C(27,28)-O(15) bond length is 1.37 Å. In the twenty-second C site, C(29,30) is bonded in a tetrahedral geometry to one H(19,20); one H(21,22); one H(23,24); and one O(15) atom. The C(29,30)-H(19,20) bond length is 1.09 Å. The C(29,30)-H(21,22) bond length is 1.10 Å. The C(29,30)-H(23,24) bond length is 1.10 Å. The C(29,30)-O(15) bond length is 1.44 Å. In the twenty-third C site, C(31,32) is bonded in a distorted bent 120 degrees geometry to one C(9), one O(17), and one O(19) atom. The C(31,32)-O(17) bond length is 1.35 Å. The C(31,32)-O(19) bond length is 1.23 Å. In the twenty-fourth C site, C(33,34) is bonded in a tetrahedral geometry to one H(25,26); one H(27,28); one H(29,30); and one O(17) atom. The C(33,34)-H(25,26) bond length is 1.09 Å. The C(33,34)-H(27,28) bond length is 1.10 Å. The C(33,34)-H(29,30) bond length is 1.10 Å. The C(33,34)-O(17) bond length is 1.45 Å. In the twenty-fifth C site, C(35) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(21), and one O(23) atom. The C(35)-O(21) bond length is 1.33 Å. The C(35)-O(23) bond length is 1.23 Å. In the twenty-sixth C site, C(36) is bonded in a distorted bent 120 degrees geometry to one C(12), one O(22), and one O(24) atom. The C(36)-O(22) bond length is 1.33 Å. The C(36)-O(24) bond length is 1.23 Å. In the twenty-seventh C site, C(37,38) is bonded in a tetrahedral geometry to one H(31), one H(33), one H(35), and one O(21) atom. The C(37,38)-H(31) bond length is 1.09 Å. The C(37,38)-H(33) bond length is 1.10 Å. The C(37,38)-H(35) bond length is 1.10 Å. The C(37,38)-O(21) bond length is 1.45 Å. In the twenty-eighth C site, C(39,40) is bonded in a distorted bent 120 degrees geometry to one C(13,14); one O(25,26); and one O(27,28) atom. The C(39,40)-O(25,26) bond length is 1.36 Å. The C(39,40)-O(27,28) bond length is 1.24 Å. In the twenty-ninth C site, C(41,42) is bonded in a tetrahedral geometry to one H(37,38); one H(39,40); one H(41,42); and one O(25,26) atom. The C(41,42)-H(37,38) bond length is 1.09 Å. The C(41,42)-H(39,40) bond length is 1.10 Å. The C(41,42)-H(41,42) bond length is 1.09 Å. The C(41,42)-O(25,26) bond length is 1.45 Å. There are twenty-seven inequivalent H sites. In the first H site, H(1,2) is bonded in a single-bond geometry to one C(17,18) atom. In the second H site, H(3,4) is bonded in a single-bond geometry to one C(17,18) atom. In the third H site, H(5,6) is bonded in a single-bond geometry to one C(17,18) atom. In the fourth H site, H(7,8) is bonded in a single-bond geometry to one C(21,22) atom. In the fifth H site, H(9,10) is bonded in a single-bond geometry to one C(21,22) atom. In the sixth H site, H(11,12) is bonded in a single-bond geometry to one C(21,22) atom. In the seventh H site, H(13) is bonded in a single-bond geometry to one C(25,26) atom. In the eighth H site, H(14) is bonded in a single-bond geometry to one C(25,26) atom. The H(14)-C(25,26) bond length is 1.09 Å. In the ninth H site, H(15) is bonded in a single-bond geometry to one C(25,26) atom. In the tenth H site, H(16) is bonded in a single-bond geometry to one C(25,26) atom. The H(16)-C(25,26) bond length is 1.10 Å. In the eleventh H site, H(17) is bonded in a single-bond geometry to one C(25,26) atom. In the twelfth H site, H(18) is bonded in a single-bond geometry to one C(25,26) atom. The H(18)-C(25,26) bond length is 1.10 Å. In the thirteenth H site, H(19,20) is bonded in a single-bond geometry to one C(29,30) atom. In the fourteenth H site, H(21,22) is bonded in a single-bond geometry to one C(29,30) atom. In the fifteenth H site, H(23,24) is bonded in a single-bond geometry to one C(29,30) atom. In the sixteenth H site, H(25,26) is bonded in a single-bond geometry to one C(33,34) atom. In the seventeenth H site, H(27,28) is bonded in a single-bond geometry to one C(33,34) atom. In the eighteenth H site, H(29,30) is bonded in a single-bond geometry to one C(33,34) atom. In the nineteenth H site, H(31) is bonded in a single-bond geometry to one C(37,38) atom. In the twentieth H site, H(32) is bonded in a single-bond geometry to one C(37,38) atom. The H(32)-C(37,38) bond length is 1.09 Å. In the twenty-first H site, H(33) is bonded in a single-bond geometry to one C(37,38) atom. In the twenty-second H site, H(34) is bonded in a single-bond geometry to one C(37,38) atom. The H(34)-C(37,38) bond length is 1.10 Å. In the twenty-third H site, H(35) is bonded in a single-bond geometry to one C(37,38) atom. In the twenty-fourth H site, H(36) is bonded in a single-bond geometry to one C(37,38) atom. The H(36)-C(37,38) bond length is 1.10 Å. In the twenty-fifth H site, H(37,38) is bonded in a single-bond geometry to one C(41,42) atom. In the twenty-sixth H site, H(39,40) is bonded in a single-bond geometry to one C(41,42) atom. In the twenty-seventh H site, H(41,42) is bonded in a single-bond geometry to one C(41,42) atom. There are twenty-six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one C(15,16) and one C(17,18) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one C(15,16) and one C(17,18) atom. The O(2)-C(15,16) bond length is 1.35 Å. The O(2)-C(17,18) bond length is 1.45 Å. In the third O site, O(3) is bonded in a single-bond geometry to one K(1) and one C(15,16) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one K(2) and one C(15,16) atom. The O(4)-C(15,16) bond length is 1.22 Å. In the fifth O site, O(5) is bonded in a single-bond geometry to one K(1) and one C(19,20) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one K(2) and one C(19,20) atom. The O(6)-C(19,20) bond length is 1.24 Å. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one C(19,20) and one C(21,22) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one C(19,20) and one C(21,22) atom. The O(8)-C(19,20) bond length is 1.36 Å. The O(8)-C(21,22) bond length is 1.45 Å. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one K(2) and one C(23) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one K(1) and one C(24) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one C(23) and one C(25,26) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one C(24) and one C(25,26) atom. The O(12)-C(25,26) bond length is 1.45 Å. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one C(27,28) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one C(27,28) atom. The O(14)-C(27,28) bond length is 1.24 Å. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one C(27,28) and one C(29,30) atom. In the sixteenth O site, O(16) is bonded in a bent 120 degrees geometry to one C(27,28) and one C(29,30) atom. The O(16)-C(27,28) bond length is 1.37 Å. The O(16)-C(29,30) bond length is 1.44 Å. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one C(31,32) and one C(33,34) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one C(31,32) and one C(33,34) atom. The O(18)-C(31,32) bond length is 1.35 Å. The O(18)-C(33,34) bond length is 1.45 Å. In the nineteenth O site, O(19) is bonded in a distorted single-bond geometry to one K(2) and one C(31,32) atom. In the twentieth O site, O(20) is bonded in a distorted single-bond geometry to one K(1) and one C(31,32) atom. The O(20)-C(31,32) bond length is 1.23 Å. In the twenty-first O site, O(21) is bonded in a bent 120 degrees geometry to one C(35) and one C(37,38) atom. In the twenty-second O site, O(22) is bonded in a bent 120 degrees geometry to one C(36) and one C(37,38) atom. The O(22)-C(37,38) bond length is 1.45 Å. In the twenty-third O site, O(23) is bonded in a distorted single-bond geometry to one K(1) and one C(35) atom. In the twenty-fourth O site, O(24) is bonded in a distorted single-bond geometry to one K(2) and one C(36) atom. In the twenty-fifth O site, O(25,26) is bonded in a bent 120 degrees geometry to one C(39,40) and one C(41,42) atom. In the twenty-sixth O site, O(27,28) is bonded in a single-bond geometry to one C(39,40) atom. Linkers: 2 COC(=O)[C]1C(C(=O)OC)=C(C(=O)OC)C(C(=O)OC)=C(C(=O)OC)C(C(=O)OC)=C1C(=O)OC ,1 [CH2]OC(=O)[C]1C(C(=O)OC)=C(C(=O)O[CH2])C(C(=O)OC)=C(C(=O)OC)C(C(=O)OC)=C1C(=O)OC ,1 [CH2]OC(=O)C1=C(C(=O)OC)C(C(=O)OC)=C(C(=O)OC)C(C(=O)OC)=C(C(=O)OC)[C]1C(=O)OC ,1 [CH2]OC(=O)C1=C(C(=O)OC)C(C(=O)O[CH2])=C(C(=O)OC)C(C(=O)OC)=C(C(=O)OC)[C]1C(=O)OC ,1 [CH2]OC(=O)C1=C(C(=O)OC)C(C(=O)OC)=C(C(=O)OC)[C](C(=O)OC)C(C(=O)OC)=C1C(=O)OC. Metal clusters: 2 [K]. The MOF has largest included sphere 2.43 A, density 1.51 g/cm3, surface area 4314.57 m2/g, accessible volume 0.12 cm3/g