Reactive nitrogen/oxygen species production by nitro/nitrosyl supramolecular ruthenium porphyrin complexes

[Display omitted] •We report the synthesis/characterization of new ruthenium-porphyrins able to generate NO.•NO photorelease, triplet state and reactive oxygen species were evaluated.•Both porphyrins produce reactive nitrogen species and reactive oxygen species.•These results could improve the photodynamic action of these compounds. This manuscript reports on new nitro/nitrosyl Ru-based complexes, which were synthesized with the purpose of using them as precursors to obtain supramolecular ruthenium porphyrin species ({TPyP[Ru(NO2)(5,5′-Mebipy)2]4}(PF6)4) and ({TPyP[Ru(NO)(5,5′-Mebipy)2]4}(PF6)12). The photochemical and photophysical properties of these porphyrin species were investigated. Results show that the complex containing nitrite is able to produce NO by homolytic O—NO cleavage (ΦNOPPh=0.05) while the {TPyP[Ru(NO)(5,5′-Mebipy)2]4}(PF6)12 does it by direct labilization (ΦNOPPh=0.53) of the RuNO bond. Furthermore, a triplet quantum yield of 0.09 and 0.27 was observed for complexes containing nitrite and nitric oxide, respectively. The reactive oxygen species quantum yield for the complex {TPyP[Ru(NO)(5,5′-Mebipy)2]4}(PF6)12 (0.78) is consistent with the sum of quantum yields NO release (0.53) and triplet state (0.27), which suggests that both processes participate in the formation of the reactive species. Our results show that combining these characteristics, NO production and triplet states, on the same platform could induce a synergic effect, leading to a considerable improvement in the photodynamic action of these complexes.