Synthesis And Characterization Of Novel Triptycenes And C₃-symmetric Organic Functional Molecules

Triptycene is a unique molecule with highly symmetric three open electron-rich cavities and three-dimensional rigid structure. It attracted numerous attention over a period of time due to its distinctive structure-properties relationship. Triptycenes have been applied to the synthesis of molecular motors, molecular gyroscopes and host-guest chemistry. Due to their availibility, many triptycenes with novel electrochemical and photochemical properties could be approached. They can also be used as low dielectric constant materials, anisotropic liquid crystal materials potentially useful in material chemistry.Screening the researches on truxene and triindole, we can easily conclude that attention had been attracted to build the size-demanding and novel target molecules through tailor-made conjugated groups to the central cores. Based on the previous works, numerous optoelectronic functional materials could be synthesized by combining and expanding various charge-transfer modes. In this thesis, we reported some triptycene derivatives and a series of C3-symmetric truxene-and triindole-based organic molecules which all showed high symmetry and good π-conjugated properties.In the first part, we provided a synthetic approach to a class of indeno-and spirofluorenylindeno-fused triptycene derivatives. They are composed by indeno-or spirofluorenylindeno-group and triptycene quinone core. The conditions for synthetic methods described here are quite mild (e.g. good yields, low reaction temperature and short reaction time). Preliminary investigations indicate that the compounds show unique three-dimensional rigid structures and excellent thermal stabilities.In the second part:we attempted to conduct the synthesis of a series of C3-symmetric truxene-and triindole-based molecules which include (1) The synthesis of alkyl-substituted triindenyl-triindole derivative composed of three indenyl rings and a triindole core with a divergence form; high symmetry and good π-conjugated properties;(2) The synthesis of phenyl-or methyl-substituted trinaphthalenyl-fused truxene derivatives. Although the poor solubility of target products caused the difficulties of synthesis and purification, they are expected to have good fluorescence properties owing to the large π-conjugated systems;(3) The synthesis of a variety of hexahalogen-substituted truxene derivatives. We developed an efficient method to synthesize2,3,7,8,12,13-hexabromotruxene by tuning reaction conditions (e.g. reaction time and temperature, the loading of starting materials), which afforded a convenient synthetic approach with excellent isolated yield (up to100%). Subsequently, we also successfully synthesized2,7,12-triiodide-3,8,13-tribromotruxene, which is a useful intermediate for further transformation towards truxene-based start-burst and hyperbranched derivatives.