Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes

We report the photophysical and photochemical properties of RuII–polypyridine complexes [Ru(bpy)(dcbpy)py2]2+ (1)2+ and [Ru(dcbpy)2py2]2+ (2)2+ (bpy = 2,2′-bipyridine, dcbpy = 4,4′-dicarboxy-2,2′-bipyridine, py = pyridine). These complexes combine a monodentate ligand with a chelate bipyridine subst...

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Autores principales: Caraballo, R.M., Rosi, P., Hodak, J.H., Baraldo, L.M.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_14341948_v2017_n30_p3612_Caraballo
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spelling todo:paper_14341948_v2017_n30_p3612_Caraballo2023-10-03T16:14:21Z Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes Caraballo, R.M. Rosi, P. Hodak, J.H. Baraldo, L.M. Carboxylate ligands Photochemistry Photosubstitution Ruthenium Temperature-dependent quantum yield We report the photophysical and photochemical properties of RuII–polypyridine complexes [Ru(bpy)(dcbpy)py2]2+ (1)2+ and [Ru(dcbpy)2py2]2+ (2)2+ (bpy = 2,2′-bipyridine, dcbpy = 4,4′-dicarboxy-2,2′-bipyridine, py = pyridine). These complexes combine a monodentate ligand with a chelate bipyridine substituted with carboxylate groups. At low pH, both complexes present metal-to-ligand charge transfer absorption bands in the visible region and room-temperature photoluminescence with long excited-state lifetimes (τ > 200 ns). At physiological pH, their absorption and emission maxima are displaced to higher energies, with a significant reduction of their emission lifetime. These species show photosubstitution of the monodentate pyridine upon irradiation at 450 nm. At low pH, the quantum yield for this process is very low, but at physiological pH, they are very active, with a φPS,450 value of 0.14 for (1)2+ and of 0.17 for (2)2+. The products of photosubstitution were identified as monoaquo complexes. Both the reactants and the products of the photosubstitution show photoluminescence, but with very different lifetimes, making it possible to monitor the reaction by the time constant of their decay. The ability of complexes (1)2+ and (2)2+ to photorelease monodentate ligands at physiological pH makes them attractive candidates for the delivery of biomolecules linked to more complex structures through the carboxylate functional group. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14341948_v2017_n30_p3612_Caraballo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Carboxylate ligands
Photochemistry
Photosubstitution
Ruthenium
Temperature-dependent quantum yield
spellingShingle Carboxylate ligands
Photochemistry
Photosubstitution
Ruthenium
Temperature-dependent quantum yield
Caraballo, R.M.
Rosi, P.
Hodak, J.H.
Baraldo, L.M.
Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
topic_facet Carboxylate ligands
Photochemistry
Photosubstitution
Ruthenium
Temperature-dependent quantum yield
description We report the photophysical and photochemical properties of RuII–polypyridine complexes [Ru(bpy)(dcbpy)py2]2+ (1)2+ and [Ru(dcbpy)2py2]2+ (2)2+ (bpy = 2,2′-bipyridine, dcbpy = 4,4′-dicarboxy-2,2′-bipyridine, py = pyridine). These complexes combine a monodentate ligand with a chelate bipyridine substituted with carboxylate groups. At low pH, both complexes present metal-to-ligand charge transfer absorption bands in the visible region and room-temperature photoluminescence with long excited-state lifetimes (τ > 200 ns). At physiological pH, their absorption and emission maxima are displaced to higher energies, with a significant reduction of their emission lifetime. These species show photosubstitution of the monodentate pyridine upon irradiation at 450 nm. At low pH, the quantum yield for this process is very low, but at physiological pH, they are very active, with a φPS,450 value of 0.14 for (1)2+ and of 0.17 for (2)2+. The products of photosubstitution were identified as monoaquo complexes. Both the reactants and the products of the photosubstitution show photoluminescence, but with very different lifetimes, making it possible to monitor the reaction by the time constant of their decay. The ability of complexes (1)2+ and (2)2+ to photorelease monodentate ligands at physiological pH makes them attractive candidates for the delivery of biomolecules linked to more complex structures through the carboxylate functional group. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
format JOUR
author Caraballo, R.M.
Rosi, P.
Hodak, J.H.
Baraldo, L.M.
author_facet Caraballo, R.M.
Rosi, P.
Hodak, J.H.
Baraldo, L.M.
author_sort Caraballo, R.M.
title Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
title_short Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
title_full Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
title_fullStr Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
title_full_unstemmed Photosubstitution of Monodentate Ligands from RuII–Dicarboxybipyridine Complexes
title_sort photosubstitution of monodentate ligands from ruii–dicarboxybipyridine complexes
url http://hdl.handle.net/20.500.12110/paper_14341948_v2017_n30_p3612_Caraballo
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