Aminocarbonyl\nFluorophores with a Strong Emissive\nInverted Solvatochromism

Three aminocarbonyls were synthesized, and their emissive\nspectral\nbehavior recorded at various solvent polarities showed marked inverted\nsolvatofluorochromism. The emission energy inversion occurs at moderate\nsolvent polarities and was found to be triggered by a change in the\nsolute–solvent interaction responsible for the stabilization\nof the highly zwitterionic excited state of the dyes, from dipolarity\nto acidity.