Push-Pull (Iso)quinoline Chromophores: Synthesis, Photophysical Properties, and Use for White-Light Emission

The photophysical properties of a series of conjugated push-pull (iso)quinolines were studied. The compounds were synthesized by well-established and straightforward methodologies. The materials exhibited not only emission solvatochromism in a variety of nonpolar solvents, but also tunable halochromism. Some of the compounds remained moderately luminescent after protonation and had a red emissive form, which was used to obtain white-light emission, both in solution and in thin films, by controlled protonation of the initially blue-green-emitting materials. This methodology has potential applications in the fabrication of white organic light-emitting diodes with two forms of a single emitter in equilibrium.