Green synthesis of luminescent blue emitters based on bistriazines with naphthalene as a π-conjugated spacer

Abstract A new series of luminescent blue emissive bistriazines is described. Bistriazines with a naphthalene spacer were prepared using a green methodology that involved microwave irradiation, solvent free conditions and a reaction time of only 10 min. The synthesis was followed by a simple purification procedure. D-σ-A-σ-π-σ-A-σ-D systems were constructed using 1,5-naphthylidene as a planar π-bridge and different donor substituents were attached to the triazine ring. UV–vis and fluorescence spectroscopy showed that the increased conjugation in bistriazines with respect to monotriazines resulted in a 40-fold increase in the photoluminescence quantum yield (Φ F ). The bistriazines were efficient blue emitters with Φ F values up to 0.87. The aggregation behavior and the optical and thermal properties of these systems have been studied. The bistriazines showed good thermal stability in conjunction with high Φ F values and they are therefore very promising materials for use in optoelectronic devices.