Abstract
Cross-coupling of bromoazulenes with carbazole allowed the synthesis of new conjugated carbazolylazulenes, such as 2-(9H-carbazolyl)-azulene and 2,6-bis(9H-carbazolyl)-azulene, in high yields. These compounds exhibit significant ability to both absorb and emit light in the visible spectrum spanning from 380 to 600 nanometers. Studies have shown that such unique photophysical characteristics, particularly the intense emission in the blue photoluminescence region (λem at 450 and 460 nm), which is absent in the original azulene, are due to the electron-donating influence of the carbazolyl groups at the C2 and C6 positions. This influence strongly alters the electronic structure of azulene, leading to conditions for the allowed HOMO →LUMO electronic transition.