4,4′-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-benzyl-1-pyridinium) Bromide

Viologens, i.e., quaternary 4,4′-bipyridinum salts, are a well-known class of functional organic compounds that have attracted in the past few decades a great deal of attention for their peculiar chemical and electrochemical properties and have therefore found numerous applications ranging from herbicides to electrochromic devices. In this paper, the synthesis and characterization of a novel viologen derivative are described. In the reported compound, the pyridinium nitrogen atoms have been quaternarized with the benzyl group and an additional unsaturated moiety, namely a 9,10-diethynylanthracene core, has been inserted between the charged pyridinium rings to extend the conjugation. Characterization by means of absorbance and diffuse reflectance UV–visible spectroscopy suggested intriguing optical and electronic properties, making this extended viologen a potential candidate for different optoelectronic applications.