The purpose of this project was to prepare fluorescent dyes that could absorb energy at relatively short wavelengths, and fluoresce in the near-IR region. To achieve this, copper- and palladium-mediated C–N couplings were used to prepare the 'cassettes', ie the carbazole derivative 3b and the carbazole-, phenothiazine-, and phenoazine-squaraines 4b– d. These compounds have carbazole, phenothiazine, and phenoazine donor-components ...
