Widely differing photochemical behavior in related octahedral {Ru-NO} 6 compounds: Intramolecular redox isomerism of the excited state controlling the photodelivery of NO
trans-[(NC)Ru(py) 4(μ-CN)Ru(py) 4(NO)] 3+ (py = pyridine) is a stable species in aqueous solution. It displays an intense absorption in the visible region of the spectrum (λ max = 518 nm; ε max = 6100 M -1 cm -1), which turns this compound into a promising agent for the photodelivery of NO. The quan...
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| Autores principales: | , , , |
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| Publicado: |
2010
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v49_n15_p6925_DeCandia http://hdl.handle.net/20.500.12110/paper_00201669_v49_n15_p6925_DeCandia |
| Aporte de: |
| Sumario: | trans-[(NC)Ru(py) 4(μ-CN)Ru(py) 4(NO)] 3+ (py = pyridine) is a stable species in aqueous solution. It displays an intense absorption in the visible region of the spectrum (λ max = 518 nm; ε max = 6100 M -1 cm -1), which turns this compound into a promising agent for the photodelivery of NO. The quantum yield for the photodelivery process resulting from irradiation with 455 nm visible light was found experimentally to be (0.06 ± 0.01)×10 -3 mol einstein -1, almost 3 orders of magnitude smaller than that in the closely related cis-[RuL(NH 3) 4(μ-pz) Ru(bpy) 2(NO)] 5+ species (L = NH 3 or pyridine, pz = pyrazine, bpy = 2,2′-bipyridine; φ NO = 0.02-0.04 mol einstein -1 depending on L) and also much smaller than the one in the mononuclear compound trans-[ClRu(py) 4(NO)] 2+ (φ NO = (1.63 ± 0.04)×10 -3 mol einstein -1). DFT computations provide an electronic structure picture of the photoactive excited states that helps to understand this apparently abnormal behavior. © 2010 American Chemical Society. |
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