Convenient synthesis of functionalized 4,4′-disubstituted-2,2′-bipyridine with extended π-system for dye-sensitized solar cell applications

Exploration of new ruthenium-based sensitizers for dye-sensitized solar cell (DSC) applications requires an easy access to multifunctionalized ligands for efficient screening of sensitizers’ properties. Based on the Horner–Emmons–Wadsworth reaction, a convenient synthetic route for the extension of the π-system on 4,4′-disubstituted-2,2′-bipyridines was used to develop a novel series of functionalized 2,2′-bipyridine ligands with either electron-withdrawing or donating end-capping group. 1H NMR spectroscopy revealed that all the new bipyridyl ligands were obtained exclusively in their fully E isomers.