No abstract

The molecules of the title compound, [Cu2Br4(C10H8N2O2)2], are centrosymmetric dimers. The CuIIatom exhibits a distorted square-pyramidal coordination geometry, with two bridging bromide ligands and the N atoms of the 4,4′-dihydroxy-2,2′-bipyridine chelate in the equatorial plane. π–π stacking and hydrogen-bonding interactions of the O—H...Br, C—H...·Br and C—H...O types consolidate the crystal packing.

The urgent need to find alternative sources of energy has been recognized as a major challenge of the 21 st century. Many ideas have been proposed, but harvesting the energy of the Sun has been identified by many as the most promising alternative to satisfy the world's increasing energy demand. Among the current technologies to harness solar energy, photovoltaics and artificial photosynthesis (photocatalysis) stand out. Although very different in their strategies, both technologies entail the same core principle, the generation of a charge-separated state. To achieve the charge-separated state, both methods require an electron acceptor that will receive the photo-electron; in most cases this role is played by C60 or its derivatives. Our research group has synthesized and characterized an octanuclear iron-oxo cluster with remarkable electrochemical properties which compares favorably with the reduction potentials of C60 and derivatives. This dissertation explores the use of this octanuclear cluster as electron acceptor for solar energy applications. vii To assess the viability of Fe8 as an electron acceptor in photocatalysis, electron donors that could coordinate to its iron atoms via phenol groups were synthesized and characterized. These electron donors were used in efforts to make molecular dyads, but coordination was not achieved. The alternative strategy studied was the preparation of Fe8-based hybrid materials that can be cast with known polymer electron donors. Several hybrid materials were prepared and their general properties investigated. These materials exhibited the desired electrochemical traits as well as the general castable behavior of the polymer host. These hybrids are now ready to be tested in polymer solar cells. viii