From benzyl to fluorenyl: enhancing photostability and modulating optoelectronic properties of para-azaquinodimethanes

Abstract

Herein, we report synthesis and the characterization of the first fluorenyl-flanked para-azaquinodimethane (F-AQM), which exhibits markedly improved photostability, a pronounced bathochromic shift in absorption, and a reduced optical bandgap compared to its benzyl-flanked analogue (AQM1). Single-crystal X-ray diffraction and theoretical calculations reveal a bent quinoidal core with twisted fluorenyl units, highlighting F-AQM as a promising quinoidal semiconductor building block.