Synthesis and Characterization of Cross-linkable Viologen Derivatives

In this study, crosslinkable allyl functional viologen derivative (ALV-Br) was synthesized with 4-4'biridyl in the presence of allyl bromide in acetonitrile and the precipitated product was separated by filtration. Chemical characterization of the obtained structure was carried out as a result of FT-IR and 1H-NMR spectra. In the cyclic voltammetry (CV) measurements performed for electrochemical characterization, a two-step reversible reduction peak attributed to viologen salts was clearly observed in the 0-0.8 V range. According to the UV-Vis absorption spectra, it is seen that they only absorb in the UV region below 400 nm in both solution and thin film. Thin films of ALV-Br salt were then spray coated in the presence of a tetrathiol-based crosslinker (pentaerythritol tetrakis(3-mercapto-propionate).In the final step, the surface morphology of the crosslinked thin film was examined by Atomic force microscopy (AFM) and compared with the results of the non-crosslinked one. Finally, the patterned film of ALV-Br could be obtained by this technique.