Synthesis and oxidative properties of metal complexes with more than one metal center.
Metal complexes can be used to facilitate electron transfer due to their ability to readily change oxidation states. Much research has been done looking at ways to maximizing electron transfer when catalyzed by metal complexes. The Goldsmith lab has previously looked at the effects of creating complexes with multiple metal tris-bipyridine centers on the ability to transfer electrons and through this process produce H2 gas. Their research included complexes with 1, 2, 3, and 4 metal centers focusing on ruthenium and iridium as metal centers. Their research has shown that both the number of centers and the metals used have an effect on the ability of the complex to be oxidized and reduced and there for and effect on the ability of the complexes to facilitate electron transfer and hydrogen production.
Further research will be done looking at the effect of the connection between metal centers. The bi-metallic complexes tested so far have been connected by carbon chains consisting of six carbons. We will be synthesizing complexes with chains of different lengths, both shorter and longer, to determine the effect of the chain length on electron transfer. This process will start with the synthesis of 2,2’-Bipyridinyl-5-carboxylic acid. The next step will be to take this compound and make a bis-bpy carbox amide where the two bpy groups are joined by a carbon chain of a known length other than the initial six carbon chain. The final step will be to add the Ru(bpy)2 group to form the bimetallic complex. The complexes’ oxidative abilities will be tested using methods such as cyclic voltammetry, and their production of H2 from water under light.