Abstract
Phenanthroline pteridinedione (pptd) is an alloxazine derivative capable of 2e/ 2H+ transfer reactions. Coordination of pptd to a Ru(II) metal center allows for the synthesis of water-soluble metal complexes capable of being reduced by as many as 6 Hatoms making them candidates to be electrochemical mediators. This thesis describes the synthesis and characterization of pptd and [Ru(bpy)2(pptd)](PF6)2(b py = 2,2-bipyridine). The dipyrido[3,2-a: 1' ,2' -c] phenazine (d ppz) and [Ru(bpy)2(d ppz) ](PF6)2 are also synthesized and studied in order to distinguish the properties of the free and coordinated pteridinedione-based pptd ligand from the well-characterized phenazine based ligand.Detailed cyclic voltammetry, coulometry and spectroelectrochemical data m protic and aprotic media are presented along with assignments for the reductions. Obtaining spectroelectrochemical data of pptd and both Ru(II) complexes proved to be challenging due to solubility issues and (presumably) competing side reactions. The effects of adding a H-bonding solvent on the reduction potentials of the metal complexes in aprotic media are also explored in an attempt to more accurately assign reductions. DFT calculations are presented on all four compounds along with TD-DFT calculations to better understand the orbitals involved in the reductions of these complexes and ligands and to compare the predicted UV-Vis spectra with empirical data. Preliminary results on catalysis of CO2 reduction by [Ru(bpy)2(pptd)](PF6)2a re also described in a number of aprotic solvents. Finally, crystal structures of pptd, [Ru(bpy)2(pptd)](PF6)2 and 5,6-dihydroxy-1,10-phenanthroline (side product from condensation reaction of pptd and 5,6-diamino-1,3-dimethyl-uracil), obtained from X-ray data, are presented.
| Date of Award | 2009 |
|---|---|
| Original language | American English |
| Awarding Institution |
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| Supervisor | Mark E. McGuire (Supervisor) |
ASJC Scopus Subject Areas
- Inorganic Chemistry