Abstract: Anna Melker
Mentor: Jonas I. Goldsmith
To impede the acceleration of global climate change and relieve our dwindling oil supplies, the development of other energy sources is imperative. Hydrogen fuel stands out as a zero emissions, clean alternative. One way to make hydrogen gas involves the photocatalytic reduction of water using transition metal complexes as light harvesting catalysts. The focus of this work will be to establish a method of measuring the hydrogen produced in such systems by analysis with gas chromatography. To begin, we will synthesize previously studied transition metal bipyridine derivatives such as Ru(bpy)3, Ru(dmphen)3, Ir(ppy)2(bpy), Co(bpy)3, Co(dtbbpy)3, Rh(bpy)3, and Rh(dtbbpy)3. We will then utilize them in a photocatalytic scheme to make hydrogen; these reactions will allow the hydrogen analysis methodology to be validated. Using the method developed for these compounds, we will examine novel multimetallic (i.e containing multiple metal centers in a single macromolecule) ruthenium and iridium complexes with cobalt and rhodium based electron relays for H2 production as well as run fluorescence and fluorescence quenching experiments on the complexes. We will attempt to answer the question of whether H2 production is enhanced when more transition metals are tethered together by bridging ligands. Ultimately, once a suitable method of gas chromatography has been found, we will focus on developing novel transition metal complexes with increased H2 output. Some compounds of interest include di-, tri- and tetramer iridium complexes and bimetallic rhodium complexes.