Reverse saturable absorption in 5,10,15, 20-Tetra(4-pyridyl)-21H,23H-porphyrin with Ruthenium outlying complexes - Barbosa Neto, Newton Martins; Oliveira, Samuel L.; Guedes, Ilde; Dinelli, Luis R.; Misoguti, Lino; Mendonça, Cleber Renato; Batista, Alzir A.; Zílio, Sérgio Carlos (Journal of the Brazilian Chemical Society, 2006)