Synthesis, spectroscopy and photophysical properties of ruthenium triazolecomplexes and their application as dye-molecules in regenerative solar cells

The complexes [Ru(dcb)(2)(L)] {L = 3-(2-hydroxyphenyl)-5-(pyridin-2-yl)-1,2 ,4-triazole (2-ppt), 3-(4-hydroxyphenyl)-5-(pyridin-2-yl)-1,2,4-triazole (4 -ppt), 3,5-bis(pyrazin-2-yl)-1,2,4-triazole (bpzt), 3-(2-hydroxyphenyl)-5-( pyrazin-2-yl)-1,2,4-triazole (2-ppzt) and dcb = 4,4'-(CO2H)(2)-2,2'-bipyrid ine} have been synthesized, spectroscopically characterized and anchored to nanocrystalline TiO2 electrodes for the conversion of light into electrici ty in regenerative solar cells. The different efficiencies observed have be en rationalized on the basis of an analytical expression relating the incid ent photon-to-current conversion efficiency (IPCE) to the kinetic parameter s of the relevant electron transfer processes involved in the solar cell.