RbP2H9(C3O2)3C3H2 crystallizes in the triclinic P-1 space group. The structure consists of one 2,3-dimethyl-1,3-butadiene molecule inside a RbP2H9(C3O2)3 framework. In the RbP2H9(C3O2)3 framework, Rb(1) is bonded in a 11-coordinate geometry to one H(2), one H(4), two equivalent H(6), one O(1), one O(2), one O(3), one O(4), one O(5), and two equivalent O(6) atoms. The Rb(1)-H(2) bond length is 3.06 Å. The Rb(1)-H(4) bond length is 3.09 Å. There is one shorter (3.10 Å) and one longer (3.15 Å) Rb(1)-H(6) bond length. The Rb(1)-O(1) bond length is 2.91 Å. The Rb(1)-O(2) bond length is 2.89 Å. The Rb(1)-O(3) bond length is 2.94 Å. The Rb(1)-O(4) bond length is 3.04 Å. The Rb(1)-O(5) bond length is 2.82 Å. There is one shorter (3.20 Å) and one longer (3.39 Å) Rb(1)-O(6) bond length. There are nine 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 P(1) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-P(1) bond length is 1.80 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(1), one C(3), and one H(1) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-H(1) bond length is 1.09 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(3) atom. The C(3)-C(4) bond length is 1.41 Å. The C(3)-H(3) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(4), and one C(5) atom. The C(4)-C(4) bond length is 1.48 Å. The C(4)-C(5) bond length is 1.41 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 H(5) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(5) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(1), one C(5), and one H(7) atom. The C(6)-H(7) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(12), one C(8), and one P(2) atom. The C(7)-C(12) bond length is 1.40 Å. The C(7)-C(8) bond length is 1.40 Å. The C(7)-P(2) bond length is 1.80 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(7) and one H(8) atom. The C(8)-H(8) bond length is 1.09 Å. In the ninth C site, C(12) is bonded in a distorted single-bond geometry to one C(7) and one H(11) atom. The C(12)-H(11) bond length is 1.09 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one C(1), one O(1), one O(2), and one O(3) atom. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.56 Å. In the second P site, P(2) is bonded in a tetrahedral geometry to one C(7), one O(4), one O(5), and one O(6) atom. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.59 Å. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a linear geometry to one Rb(1), one O(3), and one O(5) atom. The H(2)-O(3) bond length is 1.11 Å. The H(2)-O(5) bond length is 1.33 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. In the fourth H site, H(4) is bonded in a linear geometry to one Rb(1), one O(1), and one O(4) atom. The H(4)-O(1) bond length is 1.10 Å. The H(4)-O(4) bond length is 1.33 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(5) atom. In the sixth H site, H(6) is bonded in a linear geometry to two equivalent Rb(1), one O(2), and one O(6) atom. The H(6)-O(2) bond length is 1.48 Å. The H(6)-O(6) bond length is 1.04 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(6) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(8) atom. In the ninth H site, H(11) is bonded in a single-bond geometry to one C(12) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one P(1), and one H(4) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Rb(1), one P(1), and one H(6) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one P(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Rb(1), one P(2), and one H(4) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one P(2), and one H(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to two equivalent Rb(1), one P(2), and one H(6) atom. Linkers: 1 [O]P(=O)(O)c1ccc(-c2ccc(P([O])(=O)O)cc2)cc1 ,2 [O]P(O)c1ccc(-c2ccc(P(=O)(O)O)cc2)cc1 ,1 O=P(O)(O)c1ccc(-c2ccc(P(=O)(O)O)cc2)cc1. Metal clusters: 2 [Rb]. The MOF has largest included sphere 1.58 A, density 1.99 g/cm3, surface area 3764.57 m2/g, accessible volume 0.08 cm3/g