Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate

Sodium pentacyanonitrosylosmate(II) dihydrate, Na2[Os(CN)5NO]·2H2O, was synthesized by photolyzing a mixture of hexacyanoosmate(II) and nitrite ion, with further purification through ion-exchange and precipitation techniques. The compound is isostructural with the iron and ruthenium analogue species...

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Autores principales: Baraldo Victorica, Luis Mario, Olabe Iparraguirre, Jose Antonio
Publicado: 1994
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v33_n25_p5890_Baraldo
http://hdl.handle.net/20.500.12110/paper_00201669_v33_n25_p5890_Baraldo
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00201669_v33_n25_p5890_Baraldo
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spelling paper:paper_00201669_v33_n25_p5890_Baraldo2023-06-08T14:40:23Z Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate Baraldo Victorica, Luis Mario Olabe Iparraguirre, Jose Antonio Sodium pentacyanonitrosylosmate(II) dihydrate, Na2[Os(CN)5NO]·2H2O, was synthesized by photolyzing a mixture of hexacyanoosmate(II) and nitrite ion, with further purification through ion-exchange and precipitation techniques. The compound is isostructural with the iron and ruthenium analogue species. The crystals are orthorhombic (Pnnm) with a = 6.312 (1) Å, b = 12.090 (2) Å, c = 15.828 (3) Å, and Z = 4. Relevant lengths and angles within the distorted anion octahedra are compared for the three (Fe, Ru, Os) compounds. IR and UV—visible spectral data are also comparatively discussed. The results are indicative of a very strong σ-, as well as back-bonding π-interaction from Os toward nitrosyl and cyanides. The complex is electrophilically reactive toward several bases such as OH-, SH- and N2H4. With OH-, an equilibrium reaction is established, [Os(CN)5NO]2-+ 20H- ⇌ [Os(CN)5NO2]4- + H2O, with K = 42 ± 1 M-2 (I = 1 M, 25.0 °C). From the kinetic and mechanistic analysis, kobs =1.37 × 10-4 M-1 s-1, is determined by the rate of nucleophilic attack of OH- into [Os(CN)5NO]2- in the elementary step. Kinetic and equilibrium results are compared with those obtained for iron and ruthenium pentacyanonitrosyl analogues, as well as for other nitrosyl complexes containing ruthenium and osmium; thus, the different factors influencing nucleophilic rates and affinities are discussed, namely charge, radius and polarizability of the reactants, as well as the energy of the π*(NO) level. The reactions of [Os(CN)5NO]2- with other nucleophiles proceed through initial adduct formation and further decomposition. © 1994, American Chemical Society. All rights reserved. Fil:Baraldo, L.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Olabe, J.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1994 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v33_n25_p5890_Baraldo http://hdl.handle.net/20.500.12110/paper_00201669_v33_n25_p5890_Baraldo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description Sodium pentacyanonitrosylosmate(II) dihydrate, Na2[Os(CN)5NO]·2H2O, was synthesized by photolyzing a mixture of hexacyanoosmate(II) and nitrite ion, with further purification through ion-exchange and precipitation techniques. The compound is isostructural with the iron and ruthenium analogue species. The crystals are orthorhombic (Pnnm) with a = 6.312 (1) Å, b = 12.090 (2) Å, c = 15.828 (3) Å, and Z = 4. Relevant lengths and angles within the distorted anion octahedra are compared for the three (Fe, Ru, Os) compounds. IR and UV—visible spectral data are also comparatively discussed. The results are indicative of a very strong σ-, as well as back-bonding π-interaction from Os toward nitrosyl and cyanides. The complex is electrophilically reactive toward several bases such as OH-, SH- and N2H4. With OH-, an equilibrium reaction is established, [Os(CN)5NO]2-+ 20H- ⇌ [Os(CN)5NO2]4- + H2O, with K = 42 ± 1 M-2 (I = 1 M, 25.0 °C). From the kinetic and mechanistic analysis, kobs =1.37 × 10-4 M-1 s-1, is determined by the rate of nucleophilic attack of OH- into [Os(CN)5NO]2- in the elementary step. Kinetic and equilibrium results are compared with those obtained for iron and ruthenium pentacyanonitrosyl analogues, as well as for other nitrosyl complexes containing ruthenium and osmium; thus, the different factors influencing nucleophilic rates and affinities are discussed, namely charge, radius and polarizability of the reactants, as well as the energy of the π*(NO) level. The reactions of [Os(CN)5NO]2- with other nucleophiles proceed through initial adduct formation and further decomposition. © 1994, American Chemical Society. All rights reserved.
author Baraldo Victorica, Luis Mario
Olabe Iparraguirre, Jose Antonio
spellingShingle Baraldo Victorica, Luis Mario
Olabe Iparraguirre, Jose Antonio
Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
author_facet Baraldo Victorica, Luis Mario
Olabe Iparraguirre, Jose Antonio
author_sort Baraldo Victorica, Luis Mario
title Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
title_short Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
title_full Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
title_fullStr Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
title_full_unstemmed Crystal and Molecular Structure, Spectroscopic Properties, and Electrophilic Reactivity of Sodium Pentacyanonitrosylosmate(II) Dihydrate
title_sort crystal and molecular structure, spectroscopic properties, and electrophilic reactivity of sodium pentacyanonitrosylosmate(ii) dihydrate
publishDate 1994
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v33_n25_p5890_Baraldo
http://hdl.handle.net/20.500.12110/paper_00201669_v33_n25_p5890_Baraldo
work_keys_str_mv AT baraldovictoricaluismario crystalandmolecularstructurespectroscopicpropertiesandelectrophilicreactivityofsodiumpentacyanonitrosylosmateiidihydrate
AT olabeiparraguirrejoseantonio crystalandmolecularstructurespectroscopicpropertiesandelectrophilicreactivityofsodiumpentacyanonitrosylosmateiidihydrate
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