Chemistry of ternary monocarboxyterpyridine-bipyridine-trimercaptotriazine ruthenium complexes and application in dye sensitized solar cells

摘要： The synthesis of the [RuII(Hmctpy)(H2O)(Cl2)], [RuII(Hmctpy)(dmbpy)Cl]Cl and [RuII(Hmctpy)(dmbpy)(H3tmt)](PF6)2 complexes (mctpy = monocarboxyterpyridine, dmbpy = dimethylbipyridine, tmt = trimercaptotriazine) was carried out based on a vectorial design for energy transfer in dye sensitized solar cells (DSSC). The [RuII(mctpy)(dmbpy)(Hxtmt)]n complexes were fully characterized and the electrochemical and absorption/emission properties corroborated their potentially as TiO2 photosensitizing agents. However, the observed current density and open circuit voltage were rather small, imparting a low efficiency for the assembled DSSCs. The results indicated a unexpected contribution of the charge recombination effects at the electrode surface. Such effects increased with the number of deprotonated groups in the tmt ligand as they interact with the nanocrystalline TiO2 surface, capturing electrons from the conduction band.