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 it-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. H-1 NMR spectroscopy revealed that all the new bipyridyl ligands were obtained exclusively in their fully E isomers. (C) 2010 Elsevier Ltd. All rights reserved.