Heptannulated Perylene Diimides: Formation and Reactivity of Electron-Deficient Tropylium Cations and Heptafulvenes.

The development of new π-conjugated motifs opens pathways to previously unexplored classes of organic semiconductors and functional dyes. In this study, five- and seven-membered carbocycles were fused at the ortho and bay regions of electron-deficient perylenes, starting from a common dialdehyde precursor. Structural analysis of the resulting perylene tetraesters, dianhydrides, and diimides (PDIs) revealed three distinct ring-fusion patterns and defined stereochemistry.