Synthesis, optical and electrochemical properties of a series of push-pull dyes based on the 4,4-bis(4-methoxy phenyl)butadienyl donor

International audienceA series of twelve dyes based on the 4,4-bis(4-methoxyphenyl)butadienyl donor and differing by the electron acceptors have been designed and synthesized. The different dyes were characterized by UV-visible absorption spectroscopy as well as cyclic voltammetry. By fine tuning the electron-accepting ability of the fourteen selected acceptors, dyes absorbing between 400 and 650 nm could be obtained with this π-extended donor. To get a deeper insight into the optical properties, solvatochromism was investigated in 23 different solvents and remarkable linear correlations could be obtained using the Taft and Catalan solvatochromism scales. A comparison with four dyes used as reference compounds and differing from the series of twelve dyes by the structure of the electron-donating groups was also established so that the electron releasing ability of the 4,4-bis(4-methoxyphenyl)butadienyl donor could be compared with the reference ones. To prepare these four references compounds, only two electron acceptors previously used for the design of the twelve dyes have been employed. Interestingly, variation of the absorption maxima of the twelve dyes was determined as being more influenced by the polarizability of the solvent rather than by its polarity. To support the experimental results, theoretical calculations were carried out