Chemistry at the interior atoms of polycyclic aromatic hydrocarbons

• Published in: Chemical Society reviews 2015-09, Vol.44 (18), p.6464-6471
• Main Author: Scott, Lawrence T
• Format: Article
• Language: English
• ISSN: 0306-0012; 1460-4744
• DOI: 10.1039/c4cs00479e

For more than 150 years, chemical reactions that make new covalent bonds to polycyclic aromatic hydrocarbons (PAHs) have been confined almost exclusively to substitution and addition reactions on the perimeters of the compounds ("edge chemistry"). The "interior" atoms of PAHs, those belonging to three rings, almost never engage in new σ-bond-forming reactions. A compound with no edges, C 60 , was the first polycyclic carbon π-system observed to exhibit such reactivity. More recently, smaller subunits of C 60 , which we call geodesic polyarenes, have also been found to exhibit "fullerene-type chemistry" at their interior carbon atoms. These reactions are all reviewed together here for the first time. The review ends with speculation that σ-bond-forming reactions may also be observed someday even in certain planar, benzenoid PAHs, although no examples have yet been reported. Reactions that form new σ-bonds to interior carbon atoms of polycyclic aromatic hydrocarbons were unknown before the fullerene era.