Intense Blue Luminescence of 3,4,6-Triphenyl-α-pyrone in the Solid State and Its Electronic Characterization

Luminescent and electronic properties of 3,4,6-triphenyl-α-pyrones have been investigated from the standpoints of fluorophore and crystal structures. 3,4,6-Triphenyl-α-pyrones are found to emit intense blue to orange luminescence in the solid state, although the luminescence is quite weak in solution. Among these, 3a exhibits the strongest blue luminescence peaking around 470 nm with an intensity at least three times stronger than that of Alq 3 ( λ max = ca. 530 nm). Therefore, 3a can possibly be applied as a blue emitter for EL devices. Structurally, 3a has the characteristics of a dimerlike arrangement in the solid state. Due to excitonic interactions based on this molecular arrangement, the absorption band is found to shift toward longer wavelengths by about 36 nm (about 2933 cm -1 ) on going from solution to the solid state.