Phenanthrene

Phenanthrene is a polyaromatic hydrocarbon (PAH) formed of three fused benzene rings and which is found in both interstellar space and diesel exhaust. In chemistry it (and the related molecule phenanthroline) are used as ligands and which are typically bound to a central metal atom. You can find out more about this unique molecule here http://en.wikipedia.org/wiki/Phenanthrene