Colour-tunable fluorescence of single molecules based on the vibration induced emission of phenazine

Due to the vibration of the phenazine unit, compound S1 exhibits dual fluorescence in solution but one peak in the solid state. Based on this novel phenomenon and combined with the intramolecular energy transfer (IET) effect, a colour-tunable luminescence, even near white emission from a single molecule could be achieved in two different ways: controlling the polarity of the solvent and the aggregation index.