From Nitrogen to Sulfur: Investigating the Effect of Core Modification within Azaacene-Fused 21,23-Dithiaporphyrins

Modifying the core structure of porphyrin dyes significantly impacts their electronic properties. However, the structure-property relationships of azaacene-fused heteroporphyrins remain underexplored. This study presents the synthesis and electronic properties of novel azaacene-fused 21,23-dithiaporphyrins. These dyes exhibit markedly red-shifted optical properties, reaching the near-infrared (NIR) region upon protonation and emitting in the NIR region in the neutral state.