TlC4H2O3C4H5 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four isobutylene molecules and four TlC4H2O3 clusters. In each TlC4H2O3 cluster, Tl(1,2) is bonded in a 1-coordinate geometry to one O(3) atom. The Tl(1,2)-O(3) bond length is 2.80 Å. There are four inequivalent C sites. In the first C site, C(1,2) is bonded in a distorted single-bond geometry to one C(13) and one H(1,2) atom. The C(1,2)-C(13) bond length is 1.40 Å. The C(1,2)-H(1,2) bond length is 1.09 Å. In the second C site, C(3,4) is bonded in a distorted bent 120 degrees geometry to one C(13), one O(1), and one O(3) atom. The C(3,4)-C(13) bond length is 1.49 Å. The C(3,4)-O(1) bond length is 1.30 Å. The C(3,4)-O(3) bond length is 1.27 Å. In the third C site, C(9,10) is bonded in a distorted single-bond geometry to one C(13) and one O(5,6) atom. The C(9,10)-C(13) bond length is 1.42 Å. The C(9,10)-O(5,6) bond length is 1.35 Å. In the fourth C site, C(13) is bonded in a trigonal planar geometry to one C(1,2); one C(3,4); and one C(9,10) atom. There are two inequivalent H sites. In the first H site, H(1,2) is bonded in a single-bond geometry to one C(1,2) atom. In the second H site, H(13,14) is bonded in a bent 150 degrees geometry to one O(1) and one O(5,6) atom. The H(13,14)-O(1) bond length is 1.50 Å. The H(13,14)-O(5,6) bond length is 1.04 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one C(3,4) and one H(13,14) atom. In the second O site, O(3) is bonded in a single-bond geometry to one Tl(1,2) and one C(3,4) atom. In the third O site, O(5,6) is bonded in a water-like geometry to one C(9,10) and one H(13,14) atom. Linkers: 4 Cc1ccc(C([O])=O)c(O)c1. Metal clusters: 4 [Tl]. The MOF has largest included sphere 1.74 A, density 2.88 g/cm3, surface area 2508.91 m2/g, accessible volume 0.07 cm3/g