Synthesis and Spectral Properties of Push-Pull Dyes Based on Isobenzofuran Scaffolds.

A new class of push-pull dyes based on the reactive isobenzofuran core have been synthesized. The new dyes have a smaller HOMO-LUMO gap than a related class of dyes based on benzofurazan and allow for isolation of structural factors that contribute to environmental sensitivity. Experimental and theoretical evidence implicate different photophysical processes are responsible for a reversal of emissive behavior that is observed between isobenzofuran and benzofurazan analogues.