Rational design of phenothiazine (PTz) and ethylenedioxythiophene (EDOT) based donor-acceptor compounds with a molecular aggregation breaker for solid state emission in red and NIR regions

Two novel donor-acceptor (A-π-D-π-A) fluorophores based on phenothiazine (PTz) and ethylenedioxythiophene (EDOT) have been synthesized. Interestingly, an unusual π-stacking induced planarization of the crystal structure was observed for the PTz ring in the dialdehyde. The solid fluorophores exhibited emission in red (600 nm) and near infrared (NIR; 739 nm) regions with quantum yields of 8.9% and 0.9%, respectively. High quantum yields were obtained for the fluorophore doped polystyrene films.