CoC4HO3(CH2)2CHCH3 crystallizes in the trigonal R-3 space group. The structure consists of eighteen 02329_fluka molecules, thirty-six 02329_fluka molecules, and eighteen 02329_fluka molecules inside a CoC4HO3 framework. In the CoC4HO3 framework, Co(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form edge-sharing CoO5 square pyramids. The Co(1)-O(3) bond length is 2.04 Å. There is one shorter (2.03 Å) and one longer (2.08 Å) Co(1)-O(1) bond length. There is one shorter (1.99 Å) and one longer (2.03 Å) Co(1)-O(2) bond length. There are four inequivalent C sites. In the first C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(2) bond length is 1.40 Å. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(1) bond length is 1.09 Å. In the second C site, C(4) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(3) atom. The C(4)-C(1) bond length is 1.48 Å. The C(4)-C(2) bond length is 1.43 Å. In the third C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(1), and one O(3) atom. The C(1)-O(1) bond length is 1.29 Å. The C(1)-O(3) bond length is 1.27 Å. In the fourth C site, C(2) is bonded in a distorted single-bond geometry to one C(3), one C(4), and one O(2) atom. The C(2)-O(2) bond length is 1.34 Å. H(1) is bonded in a single-bond geometry to one C(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Co(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one C(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Co(1) and one C(1) atom. Linkers: 3 [O]C(=O)c1cc([O])c(C([O])=O)cc1[O]. Metal clusters: 6 [Co]. The MOF has largest included sphere 5.09 A, density 1.60 g/cm3, surface area 3676.50 m2/g, accessible volume 0.14 cm3/g