In the current work, we present the use of two free-base and two zinc-metallated porphyrin-ruthenium(II) polypyridine dyads, along with two reference porphyrin derivatives, as sensitizers in both n- and p-type DSSCs and DSPECs. Two of the dyads contain the well-known Ru(bpy)3 unit (HOOC-DMP-Ru(bpy)3 and HOOC-(Zn)DMP-Ru(bpy)3), while in the other two terpyridine-Ru(Cl)-bypiridine was used (HOOC-DMP-tpy-Ru and HOOC-(Zn)DMP-tpy-Ru). In all systems, the amide-bonding motif was utilized for the connection of the counterparts comprising each dyad. Photophysical investigation of the reported systems indicated sufficient electronic interactions for the dyads in their excited states (emission measurements). The photovoltaic measurements revealed that the presence of the ruthenium complex improves the overall performance of the dyads with the most efficient dyad being HOOC-(Zn)DMP-tpy-Ru in both n- and p-type DSSCs. Consequently, HOOC-(Zn)DMP-tpy-Ru was used to fabricate n- and p-DSPECs towards the oxidation of methoxy-benzyl alcohol and the reduction of CO2, respectively.

Light activation of dyads containing porphyrins and a catalytic ruthenium complex having a high oxidation potential (~1 V vs SCE) is investigated by time-resolved spectroscopy. It is shown that activation of the ruthenium complex occurs through oxidative quenching of the chromophore in the presence of a reversible electron acceptor. Despite the lack of driving force for intramolecular electron transfer, an efficient intramolecular oxidation of the catalyst is observed, suggesting that porphyrins are attractive chromophores to activate oxidation catalysts throughout the visible spectrum.

The synthesis of a porphyrin–RuIIpolypyridine complex where the porphyrin acts as a photoactive unit and the RuIIpolypyridine as a catalytic precursor is described.