A Substructure of "Phenylogous Cubic Graphite"

Palladium-catalyzed coupling of a dibromo hexaphenylbenzene and a hexaphenylbenzene bis(boronic acid) gave a 168-carbon polyphenylene macrocycle. Its X-ray structure is shown below. This molecule is notable both as one of the very few macrocyclic polyphenylenes known (polyphenylenes are molecules composed entirely of substituted phenyl groups) and as one of the channel substructures of phenylogous cubic graphite" (cubic graphite is a hypothetical allotrope of carbon). For a brief communication describing this molecule see "Synthesis and Structure of a Polyphenylene Macrocycle Related to 'Cubic Graphite'," X. Shen, D. M. Ho, and R. A. Pascal, Jr., Org. Lett. 2003, 5, 369-371.