π-Expanded and N-Doped Fluoranthenes

Novel π-expanded and N-doped fluoranthenes were synthesized and thoroughly investigated. These eight unsubstituted compounds are obtained in a multistep synthesis with CH activation as the last key reaction step. The structures vary in their position of π-expansion on the fluoranthene scaffold and the location of the pyridinic nitrogen atom. This facilitates an in-depth investigation of the impact of such alterations in the fluoranthene structure on their overall properties. Accordingly, optical and electrochemical properties of these polyaromatic heterocycles were investigated, and DFT/TD-DFT and NICS calculations were performed. This paper entails a thorough study on b- and l,j-expanded and N-doped fluoranthenes.