Synthesis and optical and electrochemical properties of polycyclic aromatic compounds based on bis(benzothiophene)-fused fluorene

Novel polycyclic aromatic compounds (FBTPhO3 and FBTPhO4), which are based on bis(benzothiophene)-fused fluorene functionalized with oligo(ethylene glycol)-substituted phenyl, were synthesized through an intramolecular electrophilic cyclizing reaction. Thermal measurements revealed their excellent thermal stability and amorphous state. Photoluminescence spectra suggested that they both show deep blue light emission. Cyclic voltammetry tests exhibited that the ionization potentials of FBTPhO3 and FBTPhO4 are 5.67 and 5.68 eV, respectively, implying their good inoxidizability. These compounds may be promising building blocks for high-performance optoelectronic functional materials.