Synthesis and photophysical properties of N-styrylazinones

N-Styrylazinones and 1-styrylbenzotriazine were synthesized, and their photophysical properties were investigated. (Z)- and/or (E)-N-Styrylazinones (or azine) 4 were prepared from the corresponding heterocycles 1 and benzaldehyde (3) by four methods. The absorption maxima of (Z)- and/or (E)-4a-4j were measured in four solvents. Their absorption maxima showed a moderate dependence upon solvents. The absorption maxima of (Z)-isomers were blue-shifted as compared the corresponding (E)-isomers. Emission maxima, fluorescence band half-widths, 0,0 transition energies, Stokes shifts, and quantum yields of (Z)- and/or (E)-4a, 4b, 4d, 4e and 4j were measured in organic solvents. The fluorescence spectra show moderate solvatochroism. The fluorescence properties of N-styrylheterocycles vary with every heterocycles.