Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes

The electrochemistry of the {RhNO}8 complexes [Rh(PCP tBu)(NO)][BF4] (1+), [Rh(PCP tBuCH2)(NO)][BF4] (2+), and Rh(PCPtBu)(NO)Cl (3) was studied. Both four-coordinate complexes 1+ and 2+ exhibit a reversible reduction within the CH2Cl2 solvent window. Nevertheless, the chemical or electrochemical red...

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Autores principales: Pellegrino, J., Gaviglio, C., Milstein, D., Doctorovich, F.
Formato: JOUR
Materias:
Electrochemical reductions
Electron transfer behavior
Irreversible oxidation
Irreversible reduction
Non-chlorinated solvents
One-electron reductions
Paramagnetic complexes
Spectroscopic characterization
Chlorine
Chlorine compounds
Coordination reactions
Electrolytic reduction
Electronic structure
Iodine
Paramagnetism
Rhodium
X ray diffraction
Rhodium compounds
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_02767333_v32_n21_p6555_Pellegrino
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_02767333_v32_n21_p6555_Pellegrino2023-10-03T15:16:01Z Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes Pellegrino, J. Gaviglio, C. Milstein, D. Doctorovich, F. Electrochemical reductions Electron transfer behavior Irreversible oxidation Irreversible reduction Non-chlorinated solvents One-electron reductions Paramagnetic complexes Spectroscopic characterization Chlorine Chlorine compounds Coordination reactions Electrolytic reduction Electronic structure Iodine Paramagnetism Rhodium X ray diffraction Rhodium compounds The electrochemistry of the {RhNO}8 complexes [Rh(PCP tBu)(NO)][BF4] (1+), [Rh(PCP tBuCH2)(NO)][BF4] (2+), and Rh(PCPtBu)(NO)Cl (3) was studied. Both four-coordinate complexes 1+ and 2+ exhibit a reversible reduction within the CH2Cl2 solvent window. Nevertheless, the chemical or electrochemical reduction of 1+ and 2+ in CH 2Cl2 led to the formation of the five-coordinate {RhNO}8 complexes 3 and Rh(PCPtBuCH2)(NO)Cl (4), respectively, through chloride abstraction from CH2Cl 2 by the one-electron-reduced {RhNO}9 species [Rh(PCP tBu)(NO)]• (1•) and [Rh(PCP tBuCH2)(NO)]• (2•), as has been observed for many other 17-electron paramagnetic complexes. The new complex 4 was fully characterized by multinuclear NMR techniques, IR, X-ray diffraction, CV, UV-vis, and elemental analysis. On the other hand, the five-coordinate complexes 3 and 4 show only one irreversible oxidation in CH2Cl2 and two irreversible reductions in THF. The {RhNO}9 complex 1• could be obtained quantitatively by one-electron reduction of 1+ with cobaltocene in nonchlorinated solvents and was characterized by IR, EPR, and 1H NMR in solution. Activation of carbon-halogen bonds by complex 1• was observed by studying the reactivity of 1• with some aryl halides, giving in all cases the {RhNO}8 Rh(PCPtBu)(NO)X (X = Cl -, 3, or X = I-, 6) as the only rhodium complex, while a complex with coordination of the aryl moiety was not observed as a stable final product in any case. The fate of the aryl organic radicals could be determined in some cases. In addition, DFT calculations were performed to elucidate the electronic structure of 1• and to support the observed reactivity. © 2013 American Chemical Society. Fil:Pellegrino, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gaviglio, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Doctorovich, F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_02767333_v32_n21_p6555_Pellegrino
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Electrochemical reductions
Electron transfer behavior
Irreversible oxidation
Irreversible reduction
Non-chlorinated solvents
One-electron reductions
Paramagnetic complexes
Spectroscopic characterization
Chlorine
Chlorine compounds
Coordination reactions
Electrolytic reduction
Electronic structure
Iodine
Paramagnetism
Rhodium
X ray diffraction
Rhodium compounds
spellingShingle Electrochemical reductions
Electron transfer behavior
Irreversible oxidation
Irreversible reduction
Non-chlorinated solvents
One-electron reductions
Paramagnetic complexes
Spectroscopic characterization
Chlorine
Chlorine compounds
Coordination reactions
Electrolytic reduction
Electronic structure
Iodine
Paramagnetism
Rhodium
X ray diffraction
Rhodium compounds
Pellegrino, J.
Gaviglio, C.
Milstein, D.
Doctorovich, F.
Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
topic_facet Electrochemical reductions
Electron transfer behavior
Irreversible oxidation
Irreversible reduction
Non-chlorinated solvents
One-electron reductions
Paramagnetic complexes
Spectroscopic characterization
Chlorine
Chlorine compounds
Coordination reactions
Electrolytic reduction
Electronic structure
Iodine
Paramagnetism
Rhodium
X ray diffraction
Rhodium compounds
description The electrochemistry of the {RhNO}8 complexes [Rh(PCP tBu)(NO)][BF4] (1+), [Rh(PCP tBuCH2)(NO)][BF4] (2+), and Rh(PCPtBu)(NO)Cl (3) was studied. Both four-coordinate complexes 1+ and 2+ exhibit a reversible reduction within the CH2Cl2 solvent window. Nevertheless, the chemical or electrochemical reduction of 1+ and 2+ in CH 2Cl2 led to the formation of the five-coordinate {RhNO}8 complexes 3 and Rh(PCPtBuCH2)(NO)Cl (4), respectively, through chloride abstraction from CH2Cl 2 by the one-electron-reduced {RhNO}9 species [Rh(PCP tBu)(NO)]• (1•) and [Rh(PCP tBuCH2)(NO)]• (2•), as has been observed for many other 17-electron paramagnetic complexes. The new complex 4 was fully characterized by multinuclear NMR techniques, IR, X-ray diffraction, CV, UV-vis, and elemental analysis. On the other hand, the five-coordinate complexes 3 and 4 show only one irreversible oxidation in CH2Cl2 and two irreversible reductions in THF. The {RhNO}9 complex 1• could be obtained quantitatively by one-electron reduction of 1+ with cobaltocene in nonchlorinated solvents and was characterized by IR, EPR, and 1H NMR in solution. Activation of carbon-halogen bonds by complex 1• was observed by studying the reactivity of 1• with some aryl halides, giving in all cases the {RhNO}8 Rh(PCPtBu)(NO)X (X = Cl -, 3, or X = I-, 6) as the only rhodium complex, while a complex with coordination of the aryl moiety was not observed as a stable final product in any case. The fate of the aryl organic radicals could be determined in some cases. In addition, DFT calculations were performed to elucidate the electronic structure of 1• and to support the observed reactivity. © 2013 American Chemical Society.
format JOUR
author Pellegrino, J.
Gaviglio, C.
Milstein, D.
Doctorovich, F.
author_facet Pellegrino, J.
Gaviglio, C.
Milstein, D.
Doctorovich, F.
author_sort Pellegrino, J.
title Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
title_short Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
title_full Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
title_fullStr Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
title_full_unstemmed Electron transfer behavior of pincer-type {RhNO}8 complexes: Spectroscopic characterization and reactivity of paramagnetic {RhNO}9 complexes
title_sort electron transfer behavior of pincer-type {rhno}8 complexes: spectroscopic characterization and reactivity of paramagnetic {rhno}9 complexes
url http://hdl.handle.net/20.500.12110/paper_02767333_v32_n21_p6555_Pellegrino
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