Coupling methods for 2,2’-bipyridines as precursors for novel Ru-bipyridine complexes

Coupling methods for 2,2’-bipyridines as precursors for novel Ru-bipyridine complexes

The project aims to streamline the synthesis of 2,2’-bipyridine adducts, so they can be quickly and conveniently synthesized as precursors for ligands in novel organometallic ruthenium complexes. Specifically, the compounds being synthesized are 4,4’-methylated and 5,5’-methylated, 2,2’- bipyridines. The synthesis requires the homocoupling of brominated pyridines in the presence of an air sensitive nickel catalyst. The methodology has been developed as to ensure an air-free environment by assembling the closed reaction chamber in a nitrogen glovebox. Additionally, the prior literature reported an equimolar, in situ generation of the nickel catalyst, but the efficacy of the catalyst has been increased by making the catalyst as a precursor in the same inert, moisture-free environment. The reaction is completed on a Schlenk line assembly under an inert argon atmosphere. The product is isolated and purified via extraction and sublimation. Compound characterization is carried out utilizing GC-MS, NMR, and FT-IR. Bipyridines have many applications since they are excellent bidentate ligands with complexing abilities. Once incorporated into ruthenium complexes in a collaborative project, the bipyridines will become vital to increase the photosensitivity of these complexes, which may have applications ranging from synthetic photovoltaics to anti-cancer activity.