Photochemistry of Fluorescent Azobenzenes Substituted with Azulenylpyridine Moiety

Fluorescent properties and the photoisomerization behaviour of 4-azulenylpyridine-substituted azobenzenes were investigated. All studied compounds have shown fluorescent emission in solution, originating from excited singlet state S-2 -> S-0 of azulene moiety. The substitution of the azobenzene chromophore has affected the preservation of the fluorescence emission in thin films prepared in PMMA matrix. Correlation of absorption spectra with H-1-NMR spectroscopy revealed that for all compounds the E -> Z isomerization takes place upon exposure to UV light.