Exciplex formation between a pair of synthesized AIEgens leads to white light generation: a spectroscopic exploration

Abstract

Two compounds, namely 2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol (BIMP) and (E)-ethyl 2-cyano-3-(pyren-3-yl)acrylate (ECPA), were synthesized and characterized. BIMP portrayed an interesting feature of aggregation promoted enhancement of excited state intramolecular proton transfer (ESIPT) in water. On the other hand, ECPA shows AIE emission in solution. Steady state spectroscopic studies revealed that the BIMP–ECPA ensemble in solution behaves as a white light emitter, where BIMP acts as a donor and ECPA as an acceptor. The mechanism operative behind the observed white light generation was revealed to be exciplex formation between BIMP and ECPA. The current report is the first example of white light generation from two synthesized AIEgens through exciplex formation and hence holds its own merit for a smart choice of synthesized compounds resulting in white light generation.