Acid-catalysed Aquation Research Articles

Reactivity of the Coordinated Hydroperoxo Ligand.

The reactivity of the hydroperoxo complex [Co(CN)(5)OOH](3)(-) has been studied in aqueous solution. The complex undergoes acid-catalyzed aquation (k = 1.89(5) x 10(-)(2) s(-)(1), pK(a) = 5.21(4), T = 20 degrees C, I = 0.1 M). Assuming an I(d) mechanism, this allows the relative affinity for Co(III) to be deduced as H(2)O(2) < H(2)O < HO(2)(-) and implies H(2)O(2) to be a very weak ligand. At neutral pH the hydroperoxo complex effects efficient oxygen atom transfer to L-methionine to give an intermediate identified as [Co(CN)(5)(L-methionine S-oxide)](2)(-), which then dissociates to [Co(CN)(5)OH(2)](2)(-) and L-methionine S-oxide. The reaction is acid catalyzed and is proposed to take place via nucleophilic attack of sulfur on the proximal oxygen of the hydroperoxo ligand with concerted loss of water. The significance of these results for the interaction of hydrogen peroxide with labile metal ions is discussed.

Complex-formation reactions of aquacobalamin revisited: effect of chloride on the rate and activation parameters

Complex-formation reactions of aquacobalamin were reinvestigated to clarify the role of high chloride concentrations (up to 1 mol dm–3). It was found that high chloride concentrations retard the reactions due to the formation of the less substitution-labile chloro complex, for which the formation constant was found to be 0.8 dm3 mol–1 at 25 °C and ionic strength 1.0 mol dm–3. The pH dependence of the complex formation with hydrazoic acid was also re-examined. Volumes of activation were determined for the reactions with HN3 and N3– in NaClO4 medium and are discussed in comparison with those measured in KCl medium. Direct kinetic evidence for the occurrence of a reverse, acid-catalysed aquation reaction was found and this step is characterised by an activation volume of +8.3 ± 1.6 cm3 mol–1. The results are all in agreement with the concept of a dissociative interchange substitution mechanism.

Kinetics and Mechanism of Acid Hydrolysis of Bis(dicarboxylato)carbonatochromate(III) Complexes

Abstract A study has been made of the acid-catalysed aquation reactions of three complex ions of the general formula [Cr(XX)2(CO3)]3−, where XX=oxalate, malonate, or methylmalonate, by stopped-flow spectrophotometry in the acid range 0.1–2.0 M (M=mol dm−3) and 20–35°C at an ionic strength of 2 M. Only the ring-opening reaction of the carbonate is observed, k=2.12, 3.28, and 4.02 M−1 s−1 at 25°C respectively for oxalato, malonato, and methylmalonato complexes as the subsequent decarboxylation is too fast to measure. The observed trend was explained in terms of the basicity of the coordinated inert ligands.

ChemInform Abstract: Kinetics and Mechanism of the Acid‐Catalyzed Aquation and Base Hydrolysis of Nitropentacyanoferrate(III) in Aqueous Solution. Evidence for a Pseudo‐Zero‐Order Hydrolysis Process

ChemInformVolume 19, Issue 48 Organoelement Compounds ChemInform Abstract: Kinetics and Mechanism of the Acid-Catalyzed Aquation and Base Hydrolysis of Nitropentacyanoferrate(III) in Aqueous Solution. Evidence for a Pseudo-Zero-Order Hydrolysis Process G. STOCHEL, G. STOCHEL Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorR. VAN ELDIK, R. VAN ELDIK Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorE. HEJMO, E. HEJMO Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorZ. STASICKA, Z. STASICKA Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this author G. STOCHEL, G. STOCHEL Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorR. VAN ELDIK, R. VAN ELDIK Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorE. HEJMO, E. HEJMO Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this authorZ. STASICKA, Z. STASICKA Inst. Inorg. Chem., Univ. Witten/Herdecke, D-5810 WittenSearch for more papers by this author First published: November 29, 1988 https://doi.org/10.1002/chin.198848261Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue48November 29, 1988 RelatedInformation

Kinetics and mechanism of the acid-catalyzed aquation and base hydrolysis of nitropentacyanoferrate(III) in aqueous solution. Evidence for a pseudo-zero-order hydrolysis process

Kinetics and mechanism of the acid-catalyzed aquation and base hydrolysis of nitropentacyanoferrate(III) in aqueous solution. Evidence for a pseudo-zero-order hydrolysis process

Kinetics and mechanism of the formation, substitution, isomerization, and acid-catalyzed aquation reactions of trans-(sulfito-O)cyanotetraamminecobalt(III) in aqueous solution

Kinetics and mechanism of the formation, substitution, isomerization, and acid-catalyzed aquation reactions of trans-(sulfito-O)cyanotetraamminecobalt(III) in aqueous solution

ChemInform Abstract: CONCERNING THE FORMATION AND ACID‐CATALYZED AQUATION REACTIONS OF CARBONATO‐, O‐BONDED SULFITO‐ AND NITRITOPENTAAMMINECOBALT(III) IONS

Chemischer InformationsdienstVolume 14, Issue 2 Physical Inorganic Chemistry ChemInform Abstract: CONCERNING THE FORMATION AND ACID-CATALYZED AQUATION REACTIONS OF CARBONATO-, O-BONDED SULFITO- AND NITRITOPENTAAMMINECOBALT(III) IONS R. VAN ELDIK, R. VAN ELDIKSearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author R. VAN ELDIK, R. VAN ELDIKSearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author First published: January 11, 1983 https://doi.org/10.1002/chin.198302029AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue2January 11, 1983 RelatedInformation

Mechanistic information on fast reactions of transition metal complexes using rapid scan spectrophotometry. III. The acid-catalyzed aquation of a series of Co(III) carbonato complexes in aqueous solution [1

The acid-catalyzed aquation reactions of Co(NH 3) 5OCO 2 +, β- cis-Co(edda)CO 3 − and Co(nta)CO 3 2− were re-investigated using rapid scan spectrophotometry. Direct spectral evidence for the participation of protonated and ring-opened carbonato species is now provided. The observations underline the validity of the earlier suggested decarboxylation mechanisms, and enable a comparison of the spectral data for unstable carbonato intermediates.

Mechanistic information from the effect of pressure on the formation and acid-catalyzed aquation reactions of (carbonato)pentaamminecobalt(III), -rhodium(III), and -iridium(III) ions in aqueous solution

Mechanistic information from the effect of pressure on the formation and acid-catalyzed aquation reactions of (carbonato)pentaamminecobalt(III), -rhodium(III), and -iridium(III) ions in aqueous solution

Kinetics and mechanisms of the reactions of unsymmetrical chelate complexes. Acid-catalyzed aquation of glycinatobis-(biguanide)cobalt(III) perchlorate

Abstract The presence of the unsymmetrical glycinato chelate in this complex, makes the positions of the two biguanides non-equivalent. Thus the acid-catalyzed dissociation of one or other of them, gives two different isomeric (α- and β-) diaquo- products. Up to ∼50°C, the dissociation of only one biguanide takes place with the formation of the α- diaquo product. The α- diaquo form isomerizes to the β- form at higher temperature. Direct formation of the β- form does not take place at any stage of the reaction. Aquation of the bis(biguanide) complex follows a dissociative pathway up to ∼50°C, above which it becomes a complicated one. Isomerization of the α- product takes place intramolecularly by two paths, one dependent and the other independent of acid concentration. Both the isomerization paths involve “bond-rupture” processes.

Dialkyl sulphoxides as starting materials for the preparation of alkyl-transition-metal complexes. Formation of penta-aquamethylchromium(III) and pentacyanomethylcobaltate(III) salts, and the reduction of methyl radicals by vanadium(II)

The penta-aquamethylchromium(III) ion is formed in high yield from the chromium(II)–hydrogen peroxide–dimethyl sulphoxide system in aqueous solution. The methyl-deuteriated analogue has been prepared by the corresponding reaction with [2H6]dimethyl sulphoxide. The secondary kinetic deuterium isotope effect for the acid-catalysed aquation has been measured. The analogous ‘Fenton reagents’ with pentacyanocobaltate(II) and with vanadium(II) yield the pentacyanomethylcobaltate(III) ion and methane, respectively.

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. 16. Preparation, acid-catalyzed aquation, and base hydrolysis of trans-chloro(carbonato)bis(ethylenediamine)cobalt(III) chloride monohydrate

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. 16. Preparation, acid-catalyzed aquation, and base hydrolysis of trans-chloro(carbonato)bis(ethylenediamine)cobalt(III) chloride monohydrate

ChemInform Abstract: KINETICS AND MECHANISM OF AQUATION AND FORMATION REACTIONS OF CARBONATO COMPLEXES. 15. THE ACID‐CATALYZED AQUATION OF TRANS‐CARBONATOCYANOTETRAAMMINECOBALT(III) ION AND CARBON DIOXIDE UPTAKE BY TRANS‐AQUOCYANOTETRAAMMINECOBALT(III) ION

Chemischer InformationsdienstVolume 10, Issue 44 Organoelement Compounds ChemInform Abstract: KINETICS AND MECHANISM OF AQUATION AND FORMATION REACTIONS OF CARBONATO COMPLEXES. 15. THE ACID-CATALYZED AQUATION OF TRANS-CARBONATOCYANOTETRAAMMINECOBALT(III) ION AND CARBON DIOXIDE UPTAKE BY TRANS-AQUOCYANOTETRAAMMINECOBALT(III) ION C. R. KRISHNAMOORTHY, C. R. KRISHNAMOORTHYSearch for more papers by this authorD. A. PALMER, D. A. PALMERSearch for more papers by this authorR. VAN ELDIK, R. VAN ELDIKSearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author C. R. KRISHNAMOORTHY, C. R. KRISHNAMOORTHYSearch for more papers by this authorD. A. PALMER, D. A. PALMERSearch for more papers by this authorR. VAN ELDIK, R. VAN ELDIKSearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author First published: October 30, 1979 https://doi.org/10.1002/chin.197944301AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue44October 30, 1979 RelatedInformation

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. 15. The acid-catalyzed aquation of trans-carbonatocyanotetraamminecobalt(III) ion and carbon dioxide uptake by trans-aquocyanotetraamminecobalt(III) ion [1

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. 15. The acid-catalyzed aquation of trans-carbonatocyanotetraamminecobalt(III) ion and carbon dioxide uptake by trans-aquocyanotetraamminecobalt(III) ion [1

Kinetic and spectroscopic studies with a rapid-scanning spectrometer. Part 1. Transient intermediates in the dissociation of nickel(II) polyamine complexes

Successive stages in the acid-catalysed aquation of several polyamine chelates of NiII have been characterised both optically and kinetically by means of a rapid-scanning spectrometer. Complete spectra of several new transient intermediates are reported and assigned. When two terdentate ligands, viz. diethylenetriamine (dien), are involved it is established that one is completely removed in two stages before the second starts to disengage. The stepwise acid dissociation of the [Ni(trien)(OH2)2]2+ ion (trien = triethylenetetramine) is shown to be much more complex than had previously been indicated.

Volumes of activation for isomerization and acid-catalyzed aquation reactions of diaquobis(oxalato)- and diaquobis(malonato)chromium(III) complexes from high-pressure studies in solution

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVolumes of activation for isomerization and acid-catalyzed aquation reactions of diaquobis(oxalato)- and diaquobis(malonato)chromium(III) complexes from high-pressure studies in solutionPaul L. Kendall, Geoffrey A. Lawrance, and Donald R. StranksCite this: Inorg. Chem. 1978, 17, 5, 1166–1172Publication Date (Print):May 1, 1978Publication History Published online1 May 2002Published inissue 1 May 1978https://doi.org/10.1021/ic50183a015RIGHTS & PERMISSIONSArticle Views47Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (934 KB) Get e-Alerts Get e-Alerts

Kinetics and mechanism of acid-catalyzed aquation of carbonato-(1,4,8,5,11-tetra-azacyclotetradecane)cobalt(II) ion

The acid-catalyzed aquation of the title compound has been studied over the range of 0.05<[H +]<0.5 M and 40°C at I=0.5 M. The pseudo-first-order rate constants are directly proportion to [H + for the range of acidity studied. The results have been interpreted in terms of mechanism involving acidcatalyzed dechelation followed by a rapid decarboxylation of the monodentate intermediate. At 25°C, the acid-catalyzed ring-opening rate constant, k 1, is 1.3 × 10 −3 M −1 sec −1 and the temperature variations describing this constant are ΔH*, 20.6 ± 0.4 kcal/mol and Δ* = -2.6±1.3 cal/deg mol. The results are compared with those obtained for similar carbonato (tetramine)cobalt(III) complexes.

ChemInform Abstract: KINETICS AND MECHANISM OF AQUATION AND FORMATION REACTIONS OF CARBONATO COMPLEXES PART 7, ACID‐CATALYZED AQUATION OF CARBONATO(NITRILOTRIACETATO)COBALTATE(III) ION

Chemischer InformationsdienstVolume 5, Issue 33 Organoelement Compounds ChemInform Abstract: KINETICS AND MECHANISM OF AQUATION AND FORMATION REACTIONS OF CARBONATO COMPLEXES PART 7, ACID-CATALYZED AQUATION OF CARBONATO(NITRILOTRIACETATO)COBALTATE(III) ION T. P. DASGUPTA, T. P. DASGUPTASearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author T. P. DASGUPTA, T. P. DASGUPTASearch for more papers by this authorG. M. HARRIS, G. M. HARRISSearch for more papers by this author First published: August 20, 1974 https://doi.org/10.1002/chin.197433400AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume5, Issue33August 20, 1974 RelatedInformation

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. VII. Acid-catalyzed aquation of carbonato(nitrilotriacetato)cobaltate(III) ion

Kinetics and mechanism of aquation and formation reactions of carbonato complexes. VII. Acid-catalyzed aquation of carbonato(nitrilotriacetato)cobaltate(III) ion

The acid and base hydrolysis of sulfatopentamminecobalt(III) and rhodium(III) complexes

The aquation reaction of [M(NH 3) 5SO 4] + (M = Co and Rh) and the base hydrolysis of [Rh(NH 3) 5SO 4] + have been studied kinetically. In acid solution and in the absence of added sulfate ion, the aquation rate follows the equation: R/[complex] = k + k′ H[H +], at constant ionic strenght μ = 1.0 M (NaClO 4), with the rhodium complex being slightly more labile. The activation parameters are ΔH* = 22.7 (Co) and 21.4 (Rh) kcal/mole, ΔS* = −10.0 (Co) and −13.3 (Rh) e.u., ΔH H* = 28.4 (Co) and 28.5 (Rh) kcal/mole, ΔS H* = 9.2 (Co) and 9.0 (Rh) e.u. The rate constants at 25°C are: k = 8.9 × 10 −7 (Co) and 1.6 × 10 −6 (Rh) sec −1, k′ H = 9.5 × 10 −7 (Co) and 1.1 × 10 −6 (Rh) sec − M −1. The spontaneous and acid-catalysed aquation of both sulfatopentamminemetal complexes appear to be essentially dissociative processes. The constant k, for the rhodium compound, increases with the increasing [SO 4 2− above 0.3 M at μ = 4.0 M and 65°C. This effect is discussed in connection with the equilibrium ratios Q = [aquocomplex] / [sulfatocomplex]. For both the cobalt and the rhodium compound, k decreases when [NaClO 4] increases, possibly as a consequence of the decrease of water activity. The rate of the base hydrolysis of [Rh(NH 3) 5SO 4] + follows the equation R/[complex] = k OH[OH −]. The activation parameters are ΔH OH* = 24.5 kcal/ mole and ΔS OH* = 10 e.u.. Both S N1 CB and S N2 CB mechanisms are consistent with the data although the entropy of activation is in favour of the second.