Blue-light-emitting carbazole derivates with high thermal stability

A new series of fluorescent compounds containing tricarbazolyl groups have been synthesized. The compounds have very high glass transition temperatures in the range 243–266 °C, high decomposition temperatures of 506–527 °C, and exhibit strong blue fluorescence with maximum emission wavelengths at 445–457 nm. The compounds have good solubility in common solvents even though they contain rather rigid wholly aromatic structures. The thermal stability of these compounds exhibits a marked odd–even effect corresponding to the number of phenylene bridges in the compound. In the solid, the maximum photoluminescence emission wavelength with n odd have a slight bathochromic shift in comparison to those with n even.