Coordination-Driven Self-Assemblies with a Carborane Backbone

The design and self-assembly of five new supramolecular complexes (a rectangle, a triangle, a
hexagon, and two squares) are described. These assemblies incorporate carborane building blocks and
were prepared in excellent yields (>85%). The assemblies and building blocks were characterized with
multinuclear NMR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis.
Isotopically resolved mass spectrometry data confirm the existence of the rectangle, triangle, and hexagon,
and NMR data are consistent with the formation of all five assemblies. The X-ray structures of two linear
carborane building blocks, 1,12-(4-C⋮C(C5H4N)2-p-C2B10H10 (1) and 1,12-(trans-(Pt(PEt3)2I)C⋮C)2-p-C2B10H10 (2), are reported:  1 is monoclinic, P21/c, a = 10.6791(4) Å, b = 8.0091(14) Å, c = 11.6796(4) Å,
β = 107.8461(15)°, V = 950.89(5) Å3, Z = 2; 2 is monoclinic, C2/c, a = 62.1128(10) Å, b = 22.0071(3) Å,
c = 14.0494(2) Å, β = 89.9411(8)°, V = 19204.4(5) Å3, Z = 16. Crystals of the linear linker 1 exhibit close
π−π pyridine and pyridine−B(carborane) interactions, which are discussed.