Study of Rhenium and Platinum Complexes as Photocatalysts and Synthesis of Bidentate Poly Pyridyl based Ligands

The worlds' current energy consumption is heavily dependent on fossil fuels, which has caused numerous problems, most notably global warming. A long-term response to this challenge is to find an alternative energy source, and water is potentially a carbon-neutral hydrogen source with sunlight acting as the energy source to split it. Thus, photocatalytic hydrogen generation via water splitting reactions could be a promising solution for those problems in the future. Recently, metal complexes have received much attention as new photocatalyst materials for water splitting. The Re(I) bipyridyl hydride complexes have been investigated for their properties of photochemically evolution of hydrogen gas. Functionalized 4,4'-substituted-2,2'-bipyridyl ligands have been applied to the Re(I) complexes, the result indicated a dramatic changes of the reaction time for Re-H photolysis. The terpyridine coupled square-planar Pt(II) complexes were also developed the photocatalysts. Functionalization of terpyridine with different groups is essential for this study. Therefore, a list of new 4',5,5"-trisubstituted-2,2':6',2"-terpyridines have been synthesized via Krohnke reaction, six of which have been successfully converted into corresponding platinum complexes. Inspired by the "Pacman" model, a series of new poly pyridyl based binucleating scaffolds that enable two metal sites to be held in close proximity were synthesized in this research for more efficient multielectron transformations between metal and ligand, to promote hydrogen formation.