Synthesis and optical properties of a series of thermally stable diphenylanthrazolines

摘要

A series of diphenylanthrazolines were synthesized by Friedlander condensation of 2,5-dibenzoyl-1,4-phenylenediamine and acetyl-functionalized compounds in the presence of polyphosphoric acid as catalyst, in yields ranging from 61% to 88%. The diphenylanthrazolines are thermally robust with high decomposition temperatures (>380.0 °C) and high melt transitions (317-462 °C). All of them show the lowest energy absorption bands (λ_(max)~(Abs): 394-433 nm) from the π-π~* transitions by virtue of their large molar extinction coefficients (ε = 10~4M~(-1) cm~(-1)), revealing low optical band gaps (2.59-2.80 eV). The compounds emit blue fluorescence with λ_(max)~(Em)ranging from 430 to 466 nm in dilute toluene solution.