Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes

The nucleophilic addition of OH- to [Ru(CN)5(NO)]2- leads to the N-bonded pentacyanonitroruthenate(II) ion (λmax = 320 nm, ε = 3850 dm3 mol-1 cm-1). The stoichiometry is 2:1 ([OH-]:[Ru]) and the equilibrium formation constant is 4.4 × 106 dm6 mol-2 (25 °C, I = 1 mol dm-3). A kinetic study of the for...

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Autores principales: Chevalier, A.A., Gentil, L.A., Olabe, J.A.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_14727773_v_n8_p1959_Chevalier
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spelling todo:paper_14727773_v_n8_p1959_Chevalier2023-10-03T16:17:59Z Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes Chevalier, A.A. Gentil, L.A. Olabe, J.A. The nucleophilic addition of OH- to [Ru(CN)5(NO)]2- leads to the N-bonded pentacyanonitroruthenate(II) ion (λmax = 320 nm, ε = 3850 dm3 mol-1 cm-1). The stoichiometry is 2:1 ([OH-]:[Ru]) and the equilibrium formation constant is 4.4 × 106 dm6 mol-2 (25 °C, I = 1 mol dm-3). A kinetic study of the forward reaction showed that it is first order in the concentration of each reactant, with k = 0.95 dm3 mol-1 s-1 (25 °C, I = 1 mol dm-3), ΔH‡ = 57.3 ± 3.3 kJ mol-1 and ΔS‡ = -54.0 ± 4.5 J K-1 mol-1. The mechanism involves two consecutive attacks by OH-, the first being rate determining. The reaction product decays by an aquation process, leading to [Ru(CN)5(H2O)]3- and free NO2 -. The rate constant for the dissociation reaction of [Ru(CN)5(NO2)]4- is k-N = 2.00 × 10-4 s-1 (25 °C, I = 1 mol dm-3). In the formation reaction, both nitrite (O-bound) and nitro (N-bound) linkage isomers are formed, with kO and kN being 0.23 and 0.15 dm3 mol-1 s-1 respectively (25 °C, I = 1 mol dm-3). The O-bound isomer isomerizes slowly to the thermodynamically more stable N-bound isomer. The kinetic and thermodynamic parameters have been analysed by comparison with the chemistry of the complexes [Fe(CN)5(NO)]2- and [Fe(CN)5(NO2)]4-. Fil:Olabe, J.A. 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_14727773_v_n8_p1959_Chevalier
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The nucleophilic addition of OH- to [Ru(CN)5(NO)]2- leads to the N-bonded pentacyanonitroruthenate(II) ion (λmax = 320 nm, ε = 3850 dm3 mol-1 cm-1). The stoichiometry is 2:1 ([OH-]:[Ru]) and the equilibrium formation constant is 4.4 × 106 dm6 mol-2 (25 °C, I = 1 mol dm-3). A kinetic study of the forward reaction showed that it is first order in the concentration of each reactant, with k = 0.95 dm3 mol-1 s-1 (25 °C, I = 1 mol dm-3), ΔH‡ = 57.3 ± 3.3 kJ mol-1 and ΔS‡ = -54.0 ± 4.5 J K-1 mol-1. The mechanism involves two consecutive attacks by OH-, the first being rate determining. The reaction product decays by an aquation process, leading to [Ru(CN)5(H2O)]3- and free NO2 -. The rate constant for the dissociation reaction of [Ru(CN)5(NO2)]4- is k-N = 2.00 × 10-4 s-1 (25 °C, I = 1 mol dm-3). In the formation reaction, both nitrite (O-bound) and nitro (N-bound) linkage isomers are formed, with kO and kN being 0.23 and 0.15 dm3 mol-1 s-1 respectively (25 °C, I = 1 mol dm-3). The O-bound isomer isomerizes slowly to the thermodynamically more stable N-bound isomer. The kinetic and thermodynamic parameters have been analysed by comparison with the chemistry of the complexes [Fe(CN)5(NO)]2- and [Fe(CN)5(NO2)]4-.
format JOUR
author Chevalier, A.A.
Gentil, L.A.
Olabe, J.A.
spellingShingle Chevalier, A.A.
Gentil, L.A.
Olabe, J.A.
Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
author_facet Chevalier, A.A.
Gentil, L.A.
Olabe, J.A.
author_sort Chevalier, A.A.
title Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
title_short Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
title_full Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
title_fullStr Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
title_full_unstemmed Nitrosyl-nitrite interconversion in pentacyanoruthenate(II) complexes
title_sort nitrosyl-nitrite interconversion in pentacyanoruthenate(ii) complexes
url http://hdl.handle.net/20.500.12110/paper_14727773_v_n8_p1959_Chevalier
work_keys_str_mv AT chevalieraa nitrosylnitriteinterconversioninpentacyanoruthenateiicomplexes
AT gentilla nitrosylnitriteinterconversioninpentacyanoruthenateiicomplexes
AT olabeja nitrosylnitriteinterconversioninpentacyanoruthenateiicomplexes
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