Fluorescence and photophysical properties of D-π-A push-pull systems featuring a 4,5-dicyanoimidazole unit

Absorption and fluorescence spectra and fluorescence quantum yields of 18 D-;π-A push-pull compounds were measured. The investigated chromophores consist of 4,5-dicyanoimidazole — bearing donor — substituted and systematically extended π-conjugated spacers. The influence of temperature and solvent polarity on the spectral and photophysical properties was investigated. Employing INDO/S calculations, the structure–property relationships were discussed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► On the basis of the experimental absorption and fluorescence data and calculated semiempirical spectral characteristics. ► The relationships between structure and properties of studied push–pull chromophores have been revealed. ► The obtained results are of great importance to possible testing of these substances for organic NLO.