Reversible multicolor switching via simple reactions of the AIE-characteristic molecules

A multicolor switching was achieved via simple reversible coordinationand acetalation reaction between aldehydes, tri(pentafluorophenyl)borane (BCF) and methanol. The coordination [HPB → BCF] of 4,4'-[(1E,3E)-1,2,3,4-tetraphenylbuta-1,3-diene-1,4-diyl]- dibenzaldehyde (E,E-HPB) to tri(pentafluorophenyl)borane can change the emissive wavelength from 550 to 630 nm, while transformation of the aldehyde into acetal can change the emissive wavelength from 550 to 530 nm in the presence of methanol. More important, these reactions can access reversibility easily and tune the emission color repeatedly between cyan, yellow and red. All of these dyes show typical aggregation-induced emission (AIE) or aggregation-enhanced emission (AEE) characteristics. In addition, a tunable photoluminescence mechanism is proposed based on the characterization data including NMR, XRD, MS and IR. The result may provide a new design strategy for the multicolor switches and their related applications.