Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3
The catalytic disproportionation of NH2OH has been studied in anaerobic aqueous solution, pH 6-9.3, at 25.0 °C, with Na 3[Fe(CN)5NH3]·3H2O as a precursor of the catalyst, [FeII(CN)5H2O] 3-. The oxidation products are N2, N2O, and NO+ (bound in the nitroprusside ion, NP), and NH3 is the reduction pro...
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2004
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027863_v126_n41_p13432_Alluisetti http://hdl.handle.net/20.500.12110/paper_00027863_v126_n41_p13432_Alluisetti |
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paper:paper_00027863_v126_n41_p13432_Alluisetti2023-06-08T14:22:39Z Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 Catalysis Catalyst activity Coordination reactions Nuclear magnetic resonance spectroscopy Oxidation pH effects Reduction Ultraviolet spectroscopy Catalytic disproportionation Diazene Amines ammonia azo compound diazene derivative free radical hydroxylamine nitrogen nitrogen oxide nitroprusside sodium nitroxyl derivative unclassified drug absorption spectroscopy anaerobic metabolism aqueous solution article catalyst chemical reaction disproportionation reaction gas nitrogen nuclear magnetic resonance pH Raman spectrometry reduction stoichiometry temperature Ammonia Anaerobiosis Catalysis Ferric Compounds Ferrous Compounds Free Radicals Hydrogen-Ion Concentration Hydroxylamine Kinetics Nitrogen Nitrogen Oxides Oxidation-Reduction Spectrum Analysis, Raman The catalytic disproportionation of NH2OH has been studied in anaerobic aqueous solution, pH 6-9.3, at 25.0 °C, with Na 3[Fe(CN)5NH3]·3H2O as a precursor of the catalyst, [FeII(CN)5H2O] 3-. The oxidation products are N2, N2O, and NO+ (bound in the nitroprusside ion, NP), and NH3 is the reduction product. The yields of N2/N2O increase with pH and with the concentration of NH2OH. Fast regime conditions involve a chain process initiated by the NH2 radical, generated upon coordination of NH2OH to [FeII(CN)5H 2O]3-. NH3 and nitroxyl, HNO, are formed in this fast process, and HNO leads to the production of N2, N 2O, and NP. An intermediate absorbing at 440 nm is always observed, whose formation and decay depend on the medium conditions. It was identified by UV-vis, RR, and 15NMR spectroscopies as the diazene-bound [Fe II(CN)5N2H2]3- ion and is formed in a competitive process with the radical path, still under the fast regime. At high pH's or NH2OH concentrations, an inhibited regime is reached, with slow production of only N2 and NH3. The stable red diazene-bridged [(NC)5FeHN=NHFe(CN)5] 6- ion is formed at an advanced degree of NH2OH consumption. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027863_v126_n41_p13432_Alluisetti http://hdl.handle.net/20.500.12110/paper_00027863_v126_n41_p13432_Alluisetti |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Catalysis Catalyst activity Coordination reactions Nuclear magnetic resonance spectroscopy Oxidation pH effects Reduction Ultraviolet spectroscopy Catalytic disproportionation Diazene Amines ammonia azo compound diazene derivative free radical hydroxylamine nitrogen nitrogen oxide nitroprusside sodium nitroxyl derivative unclassified drug absorption spectroscopy anaerobic metabolism aqueous solution article catalyst chemical reaction disproportionation reaction gas nitrogen nuclear magnetic resonance pH Raman spectrometry reduction stoichiometry temperature Ammonia Anaerobiosis Catalysis Ferric Compounds Ferrous Compounds Free Radicals Hydrogen-Ion Concentration Hydroxylamine Kinetics Nitrogen Nitrogen Oxides Oxidation-Reduction Spectrum Analysis, Raman |
| spellingShingle |
Catalysis Catalyst activity Coordination reactions Nuclear magnetic resonance spectroscopy Oxidation pH effects Reduction Ultraviolet spectroscopy Catalytic disproportionation Diazene Amines ammonia azo compound diazene derivative free radical hydroxylamine nitrogen nitrogen oxide nitroprusside sodium nitroxyl derivative unclassified drug absorption spectroscopy anaerobic metabolism aqueous solution article catalyst chemical reaction disproportionation reaction gas nitrogen nuclear magnetic resonance pH Raman spectrometry reduction stoichiometry temperature Ammonia Anaerobiosis Catalysis Ferric Compounds Ferrous Compounds Free Radicals Hydrogen-Ion Concentration Hydroxylamine Kinetics Nitrogen Nitrogen Oxides Oxidation-Reduction Spectrum Analysis, Raman Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| topic_facet |
Catalysis Catalyst activity Coordination reactions Nuclear magnetic resonance spectroscopy Oxidation pH effects Reduction Ultraviolet spectroscopy Catalytic disproportionation Diazene Amines ammonia azo compound diazene derivative free radical hydroxylamine nitrogen nitrogen oxide nitroprusside sodium nitroxyl derivative unclassified drug absorption spectroscopy anaerobic metabolism aqueous solution article catalyst chemical reaction disproportionation reaction gas nitrogen nuclear magnetic resonance pH Raman spectrometry reduction stoichiometry temperature Ammonia Anaerobiosis Catalysis Ferric Compounds Ferrous Compounds Free Radicals Hydrogen-Ion Concentration Hydroxylamine Kinetics Nitrogen Nitrogen Oxides Oxidation-Reduction Spectrum Analysis, Raman |
| description |
The catalytic disproportionation of NH2OH has been studied in anaerobic aqueous solution, pH 6-9.3, at 25.0 °C, with Na 3[Fe(CN)5NH3]·3H2O as a precursor of the catalyst, [FeII(CN)5H2O] 3-. The oxidation products are N2, N2O, and NO+ (bound in the nitroprusside ion, NP), and NH3 is the reduction product. The yields of N2/N2O increase with pH and with the concentration of NH2OH. Fast regime conditions involve a chain process initiated by the NH2 radical, generated upon coordination of NH2OH to [FeII(CN)5H 2O]3-. NH3 and nitroxyl, HNO, are formed in this fast process, and HNO leads to the production of N2, N 2O, and NP. An intermediate absorbing at 440 nm is always observed, whose formation and decay depend on the medium conditions. It was identified by UV-vis, RR, and 15NMR spectroscopies as the diazene-bound [Fe II(CN)5N2H2]3- ion and is formed in a competitive process with the radical path, still under the fast regime. At high pH's or NH2OH concentrations, an inhibited regime is reached, with slow production of only N2 and NH3. The stable red diazene-bridged [(NC)5FeHN=NHFe(CN)5] 6- ion is formed at an advanced degree of NH2OH consumption. |
| title |
Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| title_short |
Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| title_full |
Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| title_fullStr |
Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| title_full_unstemmed |
Metal-catalyzed anaerobic disproportionation of hydroxylamine. Role of diazene and nitroxyl intermediates in the formation of N2, N 2O, NO+, and NH3 |
| title_sort |
metal-catalyzed anaerobic disproportionation of hydroxylamine. role of diazene and nitroxyl intermediates in the formation of n2, n 2o, no+, and nh3 |
| publishDate |
2004 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027863_v126_n41_p13432_Alluisetti http://hdl.handle.net/20.500.12110/paper_00027863_v126_n41_p13432_Alluisetti |
| _version_ |
1768543729761648640 |