Effects of different substituted positions on the photophysical properties of pyrene-based sulfides

Abstract A series of new pyrene-based sulfides were synthesized by the reaction between 4-methylbenzenethiol and R-bromopyrene (R = 1( 1 ), 4( 2 ), 2( 3 )). These compounds were structurally characterized and their properties were analyzed by spectroscopy, single crystal X-ray diffraction, electrochemistry and theoretical studies. Significant effect of substituted positions on photophysical properties were observed. The p -methylphenylthio group in 1- and 4-position significantly increases the absolute fluorescence quantum yield ( Ф F ) in solid state, decreases the Ф F in solution and almost does not change the Ф F in film state compared to that of pyrene. However, this substituent in 2-position keeps the high Ф F in solution, almost does not contribute to the Ф F in solid state and significantly decreases the Ф F in film state compared to that of pyrene. Moreover, compounds 1 , 2 and 3 exhibit typical aggregation-induced emission (AIE) properties that were proved by time-resolved photoluminescence.