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.