Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study
The kinetics of the reaction between aqueous solutions of Na 2[Fe(CN)5NO]•2H2O (sodium pentacyanonitrosylferrate(ii), nitroprusside, SNP) and MeN(H)OH (N-methylhydroxylamine, MeHA) has been studied by means of UV-vis spectroscopy, using complementary solution techniques: FTIR/ATR, EPR, mass spectrom...
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paper:paper_14779226_v_n37_p5025_Gutierrez2023-06-08T16:18:19Z Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study Olabe Iparraguirre, Jose Antonio Chemical reactions Reaction kinetics Sodium Aqueous solutions Mechanistic studies Nitrosation Solutions hydroxylamine n methylhydroxylamine N-methylhydroxylamine nitroprusside sodium article chemical model chemistry electron spin resonance infrared spectroscopy kinetics mass spectrometry methodology nitrosation pH time ultraviolet spectrophotometry Electron Spin Resonance Spectroscopy Hydrogen-Ion Concentration Hydroxylamines Kinetics Mass Spectrometry Models, Chemical Nitroprusside Nitrosation Spectrophotometry, Ultraviolet Spectroscopy, Fourier Transform Infrared Time Factors The kinetics of the reaction between aqueous solutions of Na 2[Fe(CN)5NO]•2H2O (sodium pentacyanonitrosylferrate(ii), nitroprusside, SNP) and MeN(H)OH (N-methylhydroxylamine, MeHA) has been studied by means of UV-vis spectroscopy, using complementary solution techniques: FTIR/ATR, EPR, mass spectrometry and isotopic labeling (15NO), in the pH range 7.1-9.3, I = 1 M (NaCl). The main products were N-methyl-N-nitrosohydroxylamine (MeN(NO)OH) and [Fe(CN)5H2O]3-, characterized as the [Fe(CN)5(pyCONH2)]3- complex (pyCONH 2 = isonicotinamide). No reaction occurred with Me2NOH (N,N-dimethylhydroxylamine, Me2HA) as nucleophile. The rate law was: R = kexp [Fe(CN)5NO2-] × [MeN(H)OH] × [OH-], with kexp = 1.6 ± 0.2 × 105 M-2 s-1, at 25.0 °C, and ΔH # = 34 ± 3 kJ mol-1, ΔS# = -32 ± 11 J K-1 mol-1, at pH 8.0. The proposed mechanism involves the formation of a precursor associative complex between SNP and MeHA, followed by an OH--assisted reversible formation of a deprotonated adduct, [Fe(CN)5(N(O)NMeOH)]3-, and rapid dissociation of MeN(NO)OH. In excess SNP, the precursor complex reacts through a competitive one-electron-transfer path, forming the [Fe(CN)5NO]3- ion with slow production of small quantities of N2O. The stoichiometry and mechanism of the main adduct-formation path are similar to those previously reported for hydroxylamine (HA) and related nucleophiles. The nitrosated product, MeN(NO)OH, decomposes thermally at physiological temperatures, slowly yielding NO. © The Royal Society of Chemistry 2008. Fil:Olabe, J.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14779226_v_n37_p5025_Gutierrez http://hdl.handle.net/20.500.12110/paper_14779226_v_n37_p5025_Gutierrez |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Chemical reactions Reaction kinetics Sodium Aqueous solutions Mechanistic studies Nitrosation Solutions hydroxylamine n methylhydroxylamine N-methylhydroxylamine nitroprusside sodium article chemical model chemistry electron spin resonance infrared spectroscopy kinetics mass spectrometry methodology nitrosation pH time ultraviolet spectrophotometry Electron Spin Resonance Spectroscopy Hydrogen-Ion Concentration Hydroxylamines Kinetics Mass Spectrometry Models, Chemical Nitroprusside Nitrosation Spectrophotometry, Ultraviolet Spectroscopy, Fourier Transform Infrared Time Factors |
| spellingShingle |
Chemical reactions Reaction kinetics Sodium Aqueous solutions Mechanistic studies Nitrosation Solutions hydroxylamine n methylhydroxylamine N-methylhydroxylamine nitroprusside sodium article chemical model chemistry electron spin resonance infrared spectroscopy kinetics mass spectrometry methodology nitrosation pH time ultraviolet spectrophotometry Electron Spin Resonance Spectroscopy Hydrogen-Ion Concentration Hydroxylamines Kinetics Mass Spectrometry Models, Chemical Nitroprusside Nitrosation Spectrophotometry, Ultraviolet Spectroscopy, Fourier Transform Infrared Time Factors Olabe Iparraguirre, Jose Antonio Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| topic_facet |
Chemical reactions Reaction kinetics Sodium Aqueous solutions Mechanistic studies Nitrosation Solutions hydroxylamine n methylhydroxylamine N-methylhydroxylamine nitroprusside sodium article chemical model chemistry electron spin resonance infrared spectroscopy kinetics mass spectrometry methodology nitrosation pH time ultraviolet spectrophotometry Electron Spin Resonance Spectroscopy Hydrogen-Ion Concentration Hydroxylamines Kinetics Mass Spectrometry Models, Chemical Nitroprusside Nitrosation Spectrophotometry, Ultraviolet Spectroscopy, Fourier Transform Infrared Time Factors |
| description |
The kinetics of the reaction between aqueous solutions of Na 2[Fe(CN)5NO]•2H2O (sodium pentacyanonitrosylferrate(ii), nitroprusside, SNP) and MeN(H)OH (N-methylhydroxylamine, MeHA) has been studied by means of UV-vis spectroscopy, using complementary solution techniques: FTIR/ATR, EPR, mass spectrometry and isotopic labeling (15NO), in the pH range 7.1-9.3, I = 1 M (NaCl). The main products were N-methyl-N-nitrosohydroxylamine (MeN(NO)OH) and [Fe(CN)5H2O]3-, characterized as the [Fe(CN)5(pyCONH2)]3- complex (pyCONH 2 = isonicotinamide). No reaction occurred with Me2NOH (N,N-dimethylhydroxylamine, Me2HA) as nucleophile. The rate law was: R = kexp [Fe(CN)5NO2-] × [MeN(H)OH] × [OH-], with kexp = 1.6 ± 0.2 × 105 M-2 s-1, at 25.0 °C, and ΔH # = 34 ± 3 kJ mol-1, ΔS# = -32 ± 11 J K-1 mol-1, at pH 8.0. The proposed mechanism involves the formation of a precursor associative complex between SNP and MeHA, followed by an OH--assisted reversible formation of a deprotonated adduct, [Fe(CN)5(N(O)NMeOH)]3-, and rapid dissociation of MeN(NO)OH. In excess SNP, the precursor complex reacts through a competitive one-electron-transfer path, forming the [Fe(CN)5NO]3- ion with slow production of small quantities of N2O. The stoichiometry and mechanism of the main adduct-formation path are similar to those previously reported for hydroxylamine (HA) and related nucleophiles. The nitrosated product, MeN(NO)OH, decomposes thermally at physiological temperatures, slowly yielding NO. © The Royal Society of Chemistry 2008. |
| author |
Olabe Iparraguirre, Jose Antonio |
| author_facet |
Olabe Iparraguirre, Jose Antonio |
| author_sort |
Olabe Iparraguirre, Jose Antonio |
| title |
Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| title_short |
Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| title_full |
Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| title_fullStr |
Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| title_full_unstemmed |
Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study |
| title_sort |
nitrosation of n-methylhydroxylamine by nitroprusside. a kinetic and mechanistic study |
| publishDate |
2008 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14779226_v_n37_p5025_Gutierrez http://hdl.handle.net/20.500.12110/paper_14779226_v_n37_p5025_Gutierrez |
| work_keys_str_mv |
AT olabeiparraguirrejoseantonio nitrosationofnmethylhydroxylaminebynitroprussideakineticandmechanisticstudy |
| _version_ |
1768545664017367040 |