C_(20)H4(C4F8)3: A Fluorine-Containing Annulated Corannulene that Is a Better Electron Acceptor Than C_(60)

摘要

There has been increased interest in the design and applications of small polyaromatic molecules for energy conversion and storage, organic transistors and organic light-emitting diodes (OLEDs), and other emerging areas of modern technology. In particular, functionalized polycyclic aromatic hydrocarbons (PAHs) have demonstrated excellent electrical mobilities in organic thin-film transistors, in some cases even under ambient conditions.It has been suggested that the air stability of such organic materials is correlated with their electronic properties and, more specifically, with a high electron affinity. Until recently, geodesic PAHs, such as corannulene and sumanene, as well as their numerous derivatives, have not been seriously considered for optoelectronic applications because 1) they typically possess very low electron affinities (e.g. EA(C_(20)H_(10)) = 0.5(1) eV), and 2) laborious multistep syntheses with moderate-to-low yields made them practically unavailable for such studies. Although the low availability of sumanene remains unchanged, significant progress has been made recently in the large-scale synthesis of corannulene.181 Furthermore, our recent studies demonstrated that functionalization of corannulene with electron-withdrawing groups (EWGs) results in a drastic enhancement of its electron-acceptor properties.