The cis-[Ru(bipy)2(PTA)2]Cl2, trans-[Ru(bipy)2(PTA)2]OTf2 ruthenium complexes are highly water soluble and luminescent in water at room temperature. Additionally, their optical properties show a pH and temperature dependence and they show reversible redox properties in water. These complexes are eligible candidates to be inks in dye-solar cells but also good candidates for being catalysts in useful processes such as photochemical water oxidation or/and hydrogen generation from water. Particularly relevant in the context of this proposal is understanding the relationship between molecular structure/isomerism and charge distribution, and how water affects both. The novelty resides in the fact that these molecules would open the way to new water-based, green optical devices.
