Synthesis and photophysical properties of blue-color emitting compounds having multi N-methylanthranillic (MANT) chromophore

We prepared various compounds having the N-methylaminoanthranyl (MANT) moiety tethered with oligomethylene chains, and investigated the photophysical features in solution and the solid state based on the fluorescence quantum yields and lifetimes, and quantum chemical calculation. The molar absorption coefficient and fluorescence quantum yield were enhanced by an increase of the number of the MANT chromophore, resulting in an increase of the brightness as emission probes. Solid-state blue emission at room temperature was observed with moderate fluorescence quantum yields. The fluorescence rates in the solid state were found to be similar those in solution. From the results of the transient absorption measurements, the photophysical deactivation pathways in the solution were discussed. The studied multi-MANT compounds could be applicable to emissive photonic crystals and an exciton generating source for blue-color OLED.