Coordinated nitroxyl anion is produced and released as nitrous oxide by the decomposition of iridium-coordinated nitrosothiols

dc.creatorKazhdan, D
dc.creatorPerissinotti, LL
dc.creatorWatanabe, B
dc.creatorEberlin, MN
dc.creatorMilagre, HMS
dc.creatorVaz, BG
dc.creatorEstrin, DA
dc.creatorDoctorovich, F
dc.date2011
dc.date10959
dc.date2014-07-30T14:02:33Z
dc.date2015-11-26T16:41:35Z
dc.date2014-07-30T14:02:33Z
dc.date2015-11-26T16:41:35Z
dc.date.accessioned2018-03-28T23:25:51Z
dc.date.available2018-03-28T23:25:51Z
dc.identifierInorganica Chimica Acta. Elsevier Science Sa, v. 366, n. 1, n. 85, n. 90, 2011.
dc.identifier0020-1693
dc.identifierWOS:000285994200011
dc.identifier10.1016/j.ica.2010.10.013
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/57186
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/57186
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1272976
dc.descriptionThe aqueous decomposition of the iridium coordinated nitrosothiols (RSNOs) trans-K[IrCl(4)(CH(3)CN) NOS-Ph] (1), and K(2)[IrCl(5)(NOECyS)] (2, ECyS = cysteine ethyl ester), was studied by MS analysis of the gaseous products, ESI-MS, NMR, and UV-Vis spectroscopy. Bent NO (NO , nitroxyl anion), sulfenic acids and nitrite were observed as coordinated products in solution, while nitrous oxide (N(2)O) and nitrogen were detected in the gas phase. The formation of coordinated NO and N(2)O, a nitroxyl dimerization product, allows us to propose the formation of free nitroxyl (HNO) as an intermediate. Complex 1 decomposes 300 times slower than free PhSNO does. In both cases (1 and 2) kinetic results show a first order decomposition behavior and a very negative Delta S(not equal), which strongly indicates an associative rate-determining step. A proposed decomposition mechanism, supported by the experimental data and DFT calculations, involves, as the first step, nucleophilic attack of H(2)O on to the sulfur atom of the coordinated RSNO, producing an NO complex and free sulfenic acid, followed by two competing reactions: a ligand exchange reaction of this NO with the sulfenic acid or, to a minor extent, coordination of N(2)O to produce an NO / N(2)O complex which finally renders free N(2) and coordinated NO(2) . Some of the produced NO is likely to be released from the metal center producing nitroxyl by protonation and finally N(2)O by dimerization and loss of H(2)O. In conclusion, the decomposition of these coordinated RSNOs occurs through a different mechanism than for the decomposition of free RSNOs. It involves the formation of sulfenic acids and coordinated NO , which is released from the complexes and protonated at the reaction pH producing nitroxyl (HNO), and ultimately N(2)O. (C) 2010 Elsevier B.V. All rights reserved.
dc.description366
dc.description1
dc.description85
dc.description90
dc.descriptionCONICET
dc.descriptionUBA [UBACYT X065]
dc.descriptionANPCyT [PICT 2006-2396]
dc.descriptionUBA [UBACYT X065]
dc.descriptionANPCyT [PICT 2006-2396]
dc.languageen
dc.publisherElsevier Science Sa
dc.publisherLausanne
dc.publisherSuíça
dc.relationInorganica Chimica Acta
dc.relationInorg. Chim. Acta
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectIridium
dc.subjectNitroxyl
dc.subjectBent NO
dc.subjectNitrosothiol
dc.subjectDecomposition
dc.subjectSulfenic acid
dc.subjectS-nitrosothiols
dc.subjectNitric-oxide
dc.subjectBasis-sets
dc.subjectNitroprusside
dc.subjectComplexes
dc.subjectChemistry
dc.subjectThiols
dc.subjectNitrosocysteine
dc.subjectMechanisms
dc.subjectReactivity
dc.titleCoordinated nitroxyl anion is produced and released as nitrous oxide by the decomposition of iridium-coordinated nitrosothiols
dc.typeArtículos de revistas


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