Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer
The kinetics and mechanism of the reaction between nitric oxide and aquapentacyanoferrate(III) were studied in detail. Pentacyanonitrosylferrate (nitroprusside, NP) was produced quantitatively in a pseudo-first-order process. The complex-formation rate constant was found to be 0.252 ±0.004 M-1 S-1 a...
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2002
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v41_n21_p5417_Roncaroli http://hdl.handle.net/20.500.12110/paper_00201669_v41_n21_p5417_Roncaroli |
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paper:paper_00201669_v41_n21_p5417_Roncaroli2023-06-08T14:40:30Z Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer aquapentacyanoferrate dyes, reagents, indicators, markers and buffers ferric ion iron derivative nitric oxide nitroprusside sodium pentacyanoferrate (III) pyrazine derivative scavenger thiocyanic acid derivative unclassified drug algorithm article chemical reaction chemistry complex formation dissociation electron transport kinetics oxidation reduction reaction pH synthesis temperature dependence Algorithms Electron Transport Ferric Compounds Indicators and Reagents Kinetics Nitric Oxide Nitroprusside Oxidation-Reduction The kinetics and mechanism of the reaction between nitric oxide and aquapentacyanoferrate(III) were studied in detail. Pentacyanonitrosylferrate (nitroprusside, NP) was produced quantitatively in a pseudo-first-order process. The complex-formation rate constant was found to be 0.252 ±0.004 M-1 S-1 at 25.5 °C, pH 3.0 (HCIO4), and l = 0.1 M (NaCIO4), for which the activation parameters are ΔV‡=52±1 kJ mol-1,ΔS‡=-82±4JK-1 mol-1, and ΔV‡=-13.9 + 0.5 cm3 mol-1. These data disagree with earlier studies on complex-formation reactions of aquapentacyanoferrate(III), for which a dissociative interchange (Id mechanism was suggested. The aquapentacyanoferrate(II) ion was detected as a reactive intermediate in the reaction of aquapentacyanoferrate(III) with NO, by using pyrazine and thiocyanate as scavengers for this intermediate. In addition, the reactions of other [FeIII(CN)5L]n- complexes (L = NCS-, py, NO2-, and CN-) with NO were studied. These experiments also pointed to the formation of Fe(II) species as intermediates. It is proposed that aquapentacyanoferrate(III) is reduced by NO to the corresponding Fe(II) complex through a rate-determining outer-sphere electron-transfer reaction controlling the overall processes. The Fe(II) complex rapidly reacts with nitrite producing [FeII(CN)5NO2]4-, followed by the fast and irreversible conversion to NP. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v41_n21_p5417_Roncaroli http://hdl.handle.net/20.500.12110/paper_00201669_v41_n21_p5417_Roncaroli |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
aquapentacyanoferrate dyes, reagents, indicators, markers and buffers ferric ion iron derivative nitric oxide nitroprusside sodium pentacyanoferrate (III) pyrazine derivative scavenger thiocyanic acid derivative unclassified drug algorithm article chemical reaction chemistry complex formation dissociation electron transport kinetics oxidation reduction reaction pH synthesis temperature dependence Algorithms Electron Transport Ferric Compounds Indicators and Reagents Kinetics Nitric Oxide Nitroprusside Oxidation-Reduction |
| spellingShingle |
aquapentacyanoferrate dyes, reagents, indicators, markers and buffers ferric ion iron derivative nitric oxide nitroprusside sodium pentacyanoferrate (III) pyrazine derivative scavenger thiocyanic acid derivative unclassified drug algorithm article chemical reaction chemistry complex formation dissociation electron transport kinetics oxidation reduction reaction pH synthesis temperature dependence Algorithms Electron Transport Ferric Compounds Indicators and Reagents Kinetics Nitric Oxide Nitroprusside Oxidation-Reduction Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| topic_facet |
aquapentacyanoferrate dyes, reagents, indicators, markers and buffers ferric ion iron derivative nitric oxide nitroprusside sodium pentacyanoferrate (III) pyrazine derivative scavenger thiocyanic acid derivative unclassified drug algorithm article chemical reaction chemistry complex formation dissociation electron transport kinetics oxidation reduction reaction pH synthesis temperature dependence Algorithms Electron Transport Ferric Compounds Indicators and Reagents Kinetics Nitric Oxide Nitroprusside Oxidation-Reduction |
| description |
The kinetics and mechanism of the reaction between nitric oxide and aquapentacyanoferrate(III) were studied in detail. Pentacyanonitrosylferrate (nitroprusside, NP) was produced quantitatively in a pseudo-first-order process. The complex-formation rate constant was found to be 0.252 ±0.004 M-1 S-1 at 25.5 °C, pH 3.0 (HCIO4), and l = 0.1 M (NaCIO4), for which the activation parameters are ΔV‡=52±1 kJ mol-1,ΔS‡=-82±4JK-1 mol-1, and ΔV‡=-13.9 + 0.5 cm3 mol-1. These data disagree with earlier studies on complex-formation reactions of aquapentacyanoferrate(III), for which a dissociative interchange (Id mechanism was suggested. The aquapentacyanoferrate(II) ion was detected as a reactive intermediate in the reaction of aquapentacyanoferrate(III) with NO, by using pyrazine and thiocyanate as scavengers for this intermediate. In addition, the reactions of other [FeIII(CN)5L]n- complexes (L = NCS-, py, NO2-, and CN-) with NO were studied. These experiments also pointed to the formation of Fe(II) species as intermediates. It is proposed that aquapentacyanoferrate(III) is reduced by NO to the corresponding Fe(II) complex through a rate-determining outer-sphere electron-transfer reaction controlling the overall processes. The Fe(II) complex rapidly reacts with nitrite producing [FeII(CN)5NO2]4-, followed by the fast and irreversible conversion to NP. |
| title |
Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| title_short |
Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| title_full |
Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| title_fullStr |
Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| title_full_unstemmed |
Kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(III) and NO: Complex formation controlled by outer-sphere electron transfer |
| title_sort |
kinetics and mechanism of the formation of nitroprusside from aquapentacyanoferrate(iii) and no: complex formation controlled by outer-sphere electron transfer |
| publishDate |
2002 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v41_n21_p5417_Roncaroli http://hdl.handle.net/20.500.12110/paper_00201669_v41_n21_p5417_Roncaroli |
| _version_ |
1768546191404957696 |