Kinetics Of Acid Hydrolysis Research Articles

Synthesis and characterization of triaminecobalt(III) complexes and acid hydrolysis kinetics of fac-[Codpt(H 2O) nX 3− n] n+ (X = Cl, Br; n = 0,1,2)

The complexes CodptX 3 and [Codpt(H 2O)X 2]ClO 4 (X = Cl, Br; dpt = dipropylenetriamine = NH(CH 2CH 2CH 2NH 2) 2) have been prepared and characterized. Rate constants (s −1) for aqueous solution at 25 °C and μ = 0.5 M (NaClO 4), for the acid-independent sequential ractions. ▪ have been measured spectrophotometrically. For X = Cl: k 1 ⋍ 2 × 10 −2, k 2 = 1.7 × 10 −4 and k 3 = 4.8 × 10 −6, and for X = Br: k 1 ⋍ 2 × 10 −2, k 2 = 5.25 × 10 −4 and k 3 = 2.5 × 10 −5 The primary equation was found to be acid independent, while the secondary and tertiary aquations were acid-inhibited reactions. For the second step, the rate of the reaction was given by the rate equation ▪ where C t is the complex concentration in the aqua-and hydroxodihalo species, k′ 2 is the rate constant for the acid-dependent pathway and K a is the equilibrium constant between the hydroxo and aqua complex ions. The activation parameters were evaluated, for X = Cl: Δ H ≠ 2 = 106.3 ± 0.4 kJ mol −1 and Δ S ≠ 2 = 40.2 ± 1.7 J K −1 mol −, and for X = Br: Δ H ≠ 2 = 91.6 ± 0.4 kJ mol −1 and Δ S ≠ 2 = 0.4 ± 1.7 J K −1 mol −1. The results are discussed and detailed comparisons of the reactivities of these complexes with other haloaminecobalt(III) species are presented.

Stability of water-soluble vitamins and coenzymes. VIII. Kinetics of acid hydrolysis of nicotinoyl-λ-aminobutyric acid

Stability of water-soluble vitamins and coenzymes. VIII. Kinetics of acid hydrolysis of nicotinoyl-λ-aminobutyric acid

Kinetics of acid hydrolysis of the nitridotrisulfate ion

A number of nitrogen sulfonates are produced by reactions between bisulfite ions and nitrite ions in aqueous solution. Thus, their chemistry is of interest in studies of aqueous aerosols in polluted air and in wet flue gas scrubbing systems. The hydrolysis reactions of nitridotrisulfate (NTS) and hydroxysulfamate (HSA), have been thoroughly investigated. Sisler and Audrieth observed the hydrolysis reaction of NTS at several temperatures: N(SO/sub 3/)/sub 3//sup 3 -/ + H/sub 2/O ..-->.. HN(SO/sub 3/)/sub 2//sup 3 -/ + H/sup +/ + SO/sub 4//sup 2 -/. They found that the NTS hydrolysis reaction occurred much more quickly than the iminodisulfate hydrolysis reaction but did not obtain any quantitative results. The authors have studied the hydrolysis of NTS over a temperature range of 283-333 K at solution pHs ranging from 4.1 to 6.7. The influence of ionic strength was determined over a range of ..mu.. = 0.03-0.5 M.

Chloro complexes of cobalt(III) and chromium(III) with 2,2-dimethyl-1,3-diaminopropane. Synthesis, characterization, and acid hydrolysis kinetics

Preparation de trans-CoCl 2 (Me 2 tn) 2 + , mer-[CoCl(Me 2 tn)(tri)]ZnCl 4 , trans-[CoCl 2 (Me 2 tn)(en)]ClO 4 et trans-CoCl(Me 2 tn) 2 (py) 2+ . Reactivite

Complexes of Nickel(II) and Copper(II) With 5,5,7-Trimethyl-1,4-Diazepane. Preparation and Kinetics of Acid-Hydrolysis

The cyclic diamine 5,5,7-trimethyl-1,4-diazepane, tmdz, is formed by borohydride reduction of 5,7,7-trimethyl-2,3,6,7-tetrahydro-1H-1,4- diazepine , which is formed by a rapid reaction between ethanediamine and 4-methylpent-3-en-2-one. Salts of the cations [Ni( tmdz )2]2+ and [Cu( tmdz )2]2+ were prepared, and their properties are reported. The kinetics of hydrolysis of [Ni( tmdz )2]2+ and [Cu( tmdz )2]2+ and bis (1,4- diazepane )nickel(II), [Ni( dach )2]2+, in aqueous HCl/NaCl media have been studied. Reaction rates are independent of acid concentration over the ranges used . Ni2+,0.1-1 mol l-1 H+ in 1 mol l-1 Cl -, kobs(25°C) = 9.1(1)×10-7 s-1, kobs(50°C) = 2.0(1)×10-5 s-1,ΔH‡96(2)kJ mol-1,0.08-4 mol l-1, H+ in 4 mol l-1 Cl -, kobs (25°pC) = 2.0(3)°10-7 s-1. Cu2+, 0.04-1 mol l-1 H+, 1 mol l-1 Cl -, kobs (25°C) = 0.028(2) s-1, for the displacement of the second ligand . [Ni( dach )2]2+, 0.1-1 mol l-1 H+, 1 mol l-1 Cl -, kobs (25°C) = 0.051(2) s-1. [Ni( tmdz )2]2+ reacts more rapidly with NaOH/edta : 1 mol l-1 NaOH , 0.1 mol l-1, Na2(edtaH2), kobs (25°C) = 7.3(3)×10-3 s-1, 0.5 mol l-1 NaOH , 0.1 mol l-1 Na2(edtaH2), kobs (25°C) = 4.5(3)×10-3 s-1.

The kinetics of acid hydrolysis of polymeric ketone acetals

AbstractThe kinetics of acid hydrolysis of poly[(2,2‐dimethyl‐1,3‐dioxolane‐4‐yl)methyl methacrylate] and of its copolymers with methyl methacrylate in homogeneous phase was investigated by means of mass spectrometry using perdeuterated acetone as the internal standard. It was found that under conditions of a pseudomonomolecular reaction the homopolymer is capable of an acceleration process with respect to the splitting‐off of acetone according to the content of the syndiotactic dyads. The respective rate constants K0 and K1 were calculated. Characterization of the steric situation by means of models of polymeric ketonacetals and the absence of acceleration in the case of copolymers even containing only a small amount of methyl methacrylate units lead to the conclusion that the reported phenomenon is due to steric effects combined with a neighbouring group effect.

Kinetics of acid hydrolysis of corn stover

A small-scale steam-injection plug-flow reactor was developed and employed to obtain kinetic parameters under experimental conditions of potential commercial interest. Using dilute H 2SO 4 as a catalyst, glucose yields are maximized at short residence times (e.g. 6 sec) and high temperatures (e.g. 240°C). At such short residence times, glucose decomposition reactions become important and the glucose kinetic parameters were, therefore, determined in a separate study. In this study, these values were imposed in the determination of the kinetic parameters used to represent the hydrolysis of the glucan in corn stover.

The kinetics of acid hydrolysis of vinyl glycidyl diethers of glycols

1. Acid-catalytic hydrolysis of vinyl glycidyl diethers of glycols was studied by UV spectroscopy and polarography. 2. The epoxy group does not exert a specific effect on the rate of hydrolysis of the studied ethers.

Study of cyanoaquonitrosyl complexes of chromium. III. Formation of adducts of Cr(CN)(H 2O) 4NO + with Ag + and Hg 2+ and their decomposition

The paper describes the conditions for the preparation of Cr(CN)(H 2O) 4NO +, its isolation in solution and its identification on the basis of the analysis of the components, spectrophotometric and elctrochemical properties and the kinetics of acid hydrolysis. The reactions of Cr(CN)(H 2O) 4NO + with Ag + and Hg 2+ ions were studied from the point of view of the stoichiometry and equilibrium. The products of these reactions were characterized by the electronic absorption spectra and sorption on ion-exchangers. On the basis of the product properties, the course of the reactions and of analogous reactions, the structures characterized by groups CrNCHg and CrNCAg were proposed. The kinetics of the decomposition reactions of the Cr(CN)(H 2O) 4NO + adducts with Ag + and Hg 2+, giving Cr(H 2O) 5NO 2+ and Hg(CN) 2, are described and the factors affecting them are discussed.

Contribution a la detoxication d'effluents de synthese en serie oxetannique

The investigation concerns the purification of waste water from reactors where the - 3.3 dialkyloxethanes are synthesized. After a study of the kinetics of acid hydrolysis of oxethane effluents, leading preferentially to formation of recyclable biodegradable diols-1.3, treatment is envisaged along two different processes: either biological or chemical-biological, with recovery of organic compounds and recycling with practically quantitative efficiencies.

Metabolism of 2-deoxy- d-glucose in baker's yeast V. Formation of 2-deoxy-α,α′-trehalose

A non-reducing disaccharide containing both D-glucose and 2-deoxy- D-glucose (dGlc) was isolated from baker's yeast incubated with D-glucose and dGlc. The disaccharide is acid labile and alkali stable and the molar ratio D-glucose/dGlc was found to be I : I. The value for optical rotation [α] D is + 165.2°. Based on physical and chemical analysis this disaccharide was identified as 2-deoxy-α,α′-trehalose ( O-α-2- deoxy- D-glucopyranosyl-( I→ I) -O-α- D-glycopyranoside ). The kinetics of acid hydrolysis of trehalose and its 2-deoxy analogues are compared.

Deuterium isotope effect on the kinetics of aquation of dichloro(β,β′,β″-triaminotriethylamine)cobalt(III) ion

The kinetics of acid hydrolysis of Co(tren)Cl 2 + (tren = β,β′,β″-triaminotriethylamine) and Co(tren-d 6) 2 + have been studied in H 2O and D 2O at 25°. The solvent and β-deuterium isotope effects for these complexes are quite different from those observed for other Co III-amine complexes. These data indicate that the solvent isotope effect is dependent on the nature of the complex, and provide further support for the proposed distortion of tren complexes.

Further considerations of the kinetics of acid hydrolysis of cellotriose

Further considerations of the kinetics of acid hydrolysis of cellotriose

Some considerations of the kinetics of acid hydrolysis of cellotriose

Some considerations of the kinetics of acid hydrolysis of cellotriose

Kinetics and mechanism of divalent-metal ion catalyzed hydrolysis of a β-ketoimine

The kinetics of acid hydrolysis of a quadridentate β-ketoimine, bisacetylacetoneethylenediimine (H 2Ch), in the presence of divalent-metal ions have been measured at constant pH by a titrimetric procedure, using 50 per cent ( v v ) dioxane-water solutions at 30°. Divalent metal ions studied included: copper, nickel, beryllium, and magnesium ions. Pseudo-first-order rate constants, k obs., are shown to vary with the ratio C M C H2Ch , and two limiting cases are established. The first, (k′ obs) attained as the ratio approaches unity, appears to correspond to the rate of hydrolysis of the pure metal-chelate compound; the other limiting rate (k obs) is taken to be the rate of hydrolysis in the absence of metal ions. The ratio K' obs./K obs. is evaluated, and correlations with formation constants and the eléctronegativity of the metal are considered.

Facile acid hydrolysis of p-chlorobenzaldoxime and its oral inefficacy

The kinetics of acid hydrolysis of p-chlorobenzaldoxime have been studied. A polarographic assay for reactant and product has been devised. The oxime readily hydrolyzes in acid solution to form an equilibrium mixture with the products. It is expected that the half-life of this oxime would be less than 20 minutes in the human stomach and that the oral inefficacy may be ascribed to this mode of degradation.

Studies on the nucleoside arrangement in deoxyribonucleic acids I. The relationship between the production of pyrimidine nucleoside 3′5′-diphosphates and specific features of nucleotide sequence

Procedures are described for the isolation from an enzymic digest of calf thymus deoxyribonucleic acid of the series of dinucleotides all comprising cytidylic acid as one of the components. Some of the properties of these dinucleotides are reported. The content in sequential isomers has been determined in the case of adenylic-cytidylic and thymidylic-cytidylic. When the dinucleotides adenylic-cytidylic, cytidylic-cytidylic, and thymidylic-cytidylic are subjected to acid hydrolysis, they undergo decomposition at different rates, but all yield the corresponding pyrimidine nucleoside 3′,5′-diphosphate as a major product. These results, in conjunction with studies on the kinetics of acid hydrolysis of pyrimidine nucleosides and their phosphoric acid esters, permit the formulation of a mechanism of nucleoside diphosphate production from oligonucleotide precursors which is applied to the study of DNA polymers in the following paper.

The kinetics of acid hydrolysis of dipeptides.

Research Article| January 01 1956 The kinetics of acid hydrolysis of dipeptides J. I. Harris; J. I. Harris 1Hormone Research Laboratory, University of California, Berkeley, California Search for other works by this author on: This Site PubMed Google Scholar R. D. Cole; R. D. Cole 1Hormone Research Laboratory, University of California, Berkeley, California Search for other works by this author on: This Site PubMed Google Scholar N. G. Pon N. G. Pon 1Hormone Research Laboratory, University of California, Berkeley, California Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1956) 62 (1): 154–159. https://doi.org/10.1042/bj0620154 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation J. I. Harris, R. D. Cole, N. G. Pon; The kinetics of acid hydrolysis of dipeptides. Biochem J 1 January 1956; 62 (1): 154–159. doi: https://doi.org/10.1042/bj0620154 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1956 CAMBRIDGE UNIVERSITY PRESS1956 Article PDF first page preview Close Modal You do not currently have access to this content.

168. The activation energy of organic reactions. Part III. The kinetics of acid hydrolysis of esters

168. The activation energy of organic reactions. Part III. The kinetics of acid hydrolysis of esters