Creation of Ring-Fused Azulenes that Show the Unique Optical Properties

Azulene is a bicyclic aromatic compound consisting of a fused seven & horbar; & horbar; and five & horbar;membered & horbar; membered ring. In recent years, the synthesis of polycyclic aromatic compounds in which various aromatic compounds are fused to an azulene skeleton has been actively studied, and their unique optical properties have also been clarified. In this paper, we describe on the synthesis, reactivity, and optical properties of novel azulene & horbar;fused & horbar; fused aromatic compounds that have been developed by the authors' ' group.