TlBH6(C2N3)2 crystallizes in the orthorhombic P2_12_12_1 space group. Tl(1) is bonded in a 3-coordinate geometry to one N(2), one N(3), and one N(6) atom. The Tl(1)-N(2) bond length is 2.87 Å. The Tl(1)-N(3) bond length is 2.83 Å. The Tl(1)-N(6) bond length is 2.90 Å. B(1) is bonded in a tetrahedral geometry to one N(1), one N(4), one H(5), and one H(6) atom. The B(1)-N(1) bond length is 1.56 Å. The B(1)-N(4) bond length is 1.55 Å. The B(1)-H(5) bond length is 1.21 Å. The B(1)-H(6) bond length is 1.22 Å. There are four inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(3), and one H(1) atom. The C(1)-N(2) bond length is 1.33 Å. The C(1)-N(3) bond length is 1.36 Å. The C(1)-H(1) bond length is 1.08 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(3), and one H(2) atom. The C(2)-N(1) bond length is 1.35 Å. The C(2)-N(3) bond length is 1.34 Å. The C(2)-H(2) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(5), one N(6), and one H(3) atom. The C(3)-N(5) bond length is 1.33 Å. The C(3)-N(6) bond length is 1.36 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 N(4), one N(6), and one H(4) atom. The C(4)-N(4) bond length is 1.35 Å. The C(4)-N(6) bond length is 1.34 Å. The C(4)-H(4) bond length is 1.08 Å. There are six inequivalent N sites. In the first N site, N(5) is bonded in a distorted water-like geometry to one C(3) and one N(4) atom. The N(5)-N(4) bond length is 1.37 Å. In the second N site, N(6) is bonded in a water-like geometry to one Tl(1), one C(3), and one C(4) atom. In the third N site, N(4) is bonded in a distorted trigonal planar geometry to one B(1), one C(4), and one N(5) atom. In the fourth N site, N(1) is bonded in a 3-coordinate geometry to one B(1), one C(2), and one N(2) atom. The N(1)-N(2) bond length is 1.37 Å. In the fifth N site, N(2) is bonded in a distorted single-bond geometry to one Tl(1), one C(1), and one N(1) atom. In the sixth N site, N(3) is bonded in a water-like geometry to one Tl(1), one C(1), and one C(2) atom. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. 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 single-bond geometry to one C(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one B(1) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one B(1) atom. Linkers: 1 [BH2](n1cncn1)N1[CH]N=C[N]1. Metal clusters: . The MOF has largest included sphere 1.70 A, density 2.81 g/cm3, surface area 2755.87 m2/g, accessible volume 0.06 cm3/g