Mechanochromic Luminescence and Solid-State Circularly Polarized Luminescence of a Chiral Diamine-Linked Bispyrene

Despite the recent increased interest in organic small molecule luminophores that exhibit circularly polarized luminescence (CPL) or mechanochromic luminescence (MCL), MCL behavior in chiral luminophores that display solid-state CPL still remains elusive. Herein, it is reported that a chiral diamine-linked bispyrene derivative exhibits a rare MCL behavior in response to two different types of mechanical stimuli, namely utrasonication and grinding. Moreover, an unprecedented switching of solid-state CPL has been achieved for the chiral bispyrene between two states that can respond to the different mechanical stimuli. These findings should help to advance the development of practical CPL materials.