Synthesis and photophysical properties of novel butterfly-shaped blue emitters based on pyrene

Abstract

Using 1,3,5,9-tetrabromo-7-tert-butylpyrene as the bromide precursor, a series of novel butterfly-shaped 1,3,5,9-tetraaryl substituted pyrene derivatives were synthesized by the Suzuki–Miyaura cross-coupling reaction. Their thermal, photophysical, electrochemical and related properties were systematically investigated. All compounds were found to exhibit high thermal stabilities with decomposition temperatures (T_d) of up to 300 °C. All compounds show highly blue fluorescence emissions in the spectral region of 412–469 nm in solution (Φ_f: 0.45–0.92) and 410–470 nm in the solid- state (Φ_f: 0.48–0.75). It is noteworthy that these butterfly-shaped pyrenes 4 possess low-lying HOMO levels ranging from −4.76 to −5.93 eV, which make them promising candidates in OLED applications.