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

• Main Author: Barbosa, Marília Imaculada Frazão
• Publication Date: 2017
• Other Authors: Gimenez Parra, Gustavo, Correa, Rodrigo de Souza, Sampaio, Renato Neiva, Magno, Lais Nogueira, Silva, Rodrigo Costa, Doriguetto, Antônio Carlos, Ellena, Javier Alcides, Barbosa Neto, Newton Martins, Batista, Alzir Azevedo, Gonçalves, Pablo José
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFOP
• Download full: http://www.repositorio.ufop.br/handle/123456789/9630; https://doi.org/10.1016/j.jphotochem.2017.01.028
• topic: Photorelease; Triplet states; Photophysical properties

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)(5,50-Mebipy)2]4}(PF6)4) and ({TPyP[Ru(NO)(5,50-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 (FPPh NO = 0.05) while the {TPyP[Ru (NO)(5,50-Mebipy)2]4}(PF6)12 does it by direct labilization (FPPh NO = 0.53) of the Ru NO 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) (5,50-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.