Determination of the Rates of Formation and Hydrolysis of the Schiff Bases Formed by Pyridoxal 5′-Phosphate with Copolypeptides Containing L-Lysine and Aromatic L-Amino Acids

The apparent rate constants of formation (k₁) and hydrolysis (k₂) of the Schiff bases formed between pyridoxal 5′-phosphate and the poly(L -Lys,L -Trp)4 : 1 copolymer at different pH values, a temperature of 25 °C and an ionic strength of 0.1 M were determined. The individual rate constants of formation and hydrolysis of the Schiff bases of pyridoxal 5′-phosphate with poly(L -Lys,L -Trp)4 : 1, poly(L -Lys,L -Tyr)4 : 1, and poly(L -Lys,L -Phe)1 : 1 corresponding to the different chemical species present in the medium as a function of its acidity were also determined, as were the pK values for the Schiff bases. The significance of the interactions between the pyridine ring in pyridoxal 5′-phosphate and the aromatic ring in the L -phenylalanine, L -tyrosine, and L -tryptophan side chains is demonstrated.     

Theoretical and experimental studies of the diketene system: Product branching decomposition rate constants and energetics of isomers

The kinetics and mechanism for the thermal decomposition of diketene have been studied in the temperature range 510–603 K using highly diluted mixtures with Ar as a diluent. The concentrations of diketene, ketene, and CO₂ were measured by FTIR spectrometry using calibrated standard mixtures. Two reaction channels were identified. The rate constants for the formation of ketene (k₁) and CO₂ (k₂) have been determined and compared with the values predicted by the Rice–Ramsperger–Kassel–Marcus (RRKM) theory for the branching reaction. The first-order rate constants, k₁ (s⁻¹) = 10^{15.74 ± 0.72} exp(−49.29 (kcal mol⁻¹) (±1.84)/RT) and k₂ (s⁻¹) = 10^{14.65 ± 0.87} exp(−49.01 (kcal mol⁻¹) (±2.22)/RT); the bulk of experimental data agree well with predicted results. The heats of formation of ketene, diketene, cyclobuta-1,3-dione, and cyclobuta-1,2-dione at 298 K computed from the G2M scheme are −11.1, −45.3, −43.6, and −40.3 kcal mol⁻¹, respectively. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 580–590, 2007     

Kinetics of the alkaline hydrolysis of fenuron in aqueous and micellar media

The kinetics of the hydrolysis of fenuron in sodium hydroxide has been investigated spectrometrically in an aqueous medium and in cationic micelles of cetyltrimethylammonium bromide (CTAB) medium. The reaction follows first‐order kinetics with respect to [fenuron] in both the aqueous and micellar media. The rate of hydrolysis increases with the increase in [NaOH] in the lower concentration range but shows a leveling behavior at higher concentrations. The reaction followed the rate equation, 1/k_obs = 1/k + 1/(kK[OH^?]), where k_obs is the observed rate constant, k is rate constant in aqueous medium, and k is the equilibrium constant for the formation of hydroxide addition product. The cationic CTAB micelles enhanced the rate of hydrolytic reaction. In both aqueous and micellar pseudophases, the hydrolysis of fenuron presumably occurs via an addition–elimination mechanism in which an intermediate hydroxide addition complex is formed. The added salts decrease the rate of reaction. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 638–644, 2007     

Ruthenium(III), osmium(VIII) and ruthenium(III) + osmium(VIII) catalysed oxidations ofi-propanol by N-bromosuccinimide in basic solution

Summary The oxidation ofi-propanol (IPA) by N-bromosuccinimide (NBS) in basic solution was investigated separately in the presence of Ru^III, Os^VIII and Ru^III + Os^VIII ions. The order in [IPA] was found to be 0.7, 0.5 and 0.3 respectively in the above three cases in the concentration range studied. The order in [NBS] was unity in the presence of Ru^III chloride but was found to be zero in the case of Os^VIII and Ru^III+Os^VIII catalysis. The order in [metalion] was found to be nearly unity in all the three catalysed reactions. Increase in [^–OH] increased the rate of reaction while addition of succinimide retarded the rate of reaction. Decrease in dielectric constantsof the medium decreased the rate of oxidation. The pseudo first order rate constants (k), zero order rate constants (k₀) and the formation constants (k_f) of the substrate-catalyst complexes and the thermodynamic parameters have been evaluated. Suitable mechanisms in conformity with the experimental observations have been proposed for the three catalysed reactions.     

Simulation of the kinetics of adenosine 5′-triphosphate hydrolysis catalyzed by the Cu2+ ion: The role of conformation and the catalytic effect of the OH− ion

The hydrolysis kinetics of the dimeric complex (CuATP^2? · OH₂)₂ {D} up to ≈40% ATP conversion at 25°C, pH 5.7–7.8, and [Cu · ATP]₀ = (2.07 ± 0.03) × 10^?3 mol/l is analyzed by numerical simulation. CuADP^? + P_i (P_i is an inorganic phosphate) form from DOH^?, and the latter forms rapidly from D. The abstraction of H⁺ from the coordinated H₂O molecule is an irreversible reaction involving an OH^? ion from the medium. The maximum possible DOH^? concentration at a given pH is reached at the initial stage of hydrolysis (0.3–6.0 min after the initiation of hydrolysis). CuADP^? + P_i form from D via two consecutive irreversible steps. The ADP buildup rate in the process is determined by the reversible conformational transformation of DOH^? resulting in a pentacovalent intermediate (IntK). OH^? ions from the medium are involved both in IntK formation and in the reverse reaction and are a hydrolysis inhibitor. AMP forms from the intermediate IntK₃, which forms reversibly from DOH^?, OH^? ions from the medium being involved in the forward and reverse reactions. This is followed by irreversible (AMPH)^? formation involving H₃O⁺ ions from the medium. The rate and equilibrium constants are determined for the formation and decomposition of hydrolysis intermediates. The concentrations of the intermediates are plotted versus time for various pH values. The structures of the intermediates are suggested. The causes of a peak appearing in the initial ADP formation rate versus pH curve are analyzed.     

INTERMEDIATES IN THE PHOTOCONVERSION OF FUNCTIONAL PHYTOCHROME IN FERN SPORES OF Dryopteris–II. In vivo KINETICS OF THE DECAY OF Ii700 AND OF THE FORMATION OF Pfr STUDIED WITH A DOUBLE-LASER APPARATUS*

Abstract— Photoconversion of the red-light-absorbing form of phytochrome, P_r, to the far-red-light-absorbing form, P_fr, was investigated in vivo at 22°C with 600 or 800 ns laser pulses of high spectral purity and induction of spore germination in Dryopteris paleacea was used as indicator for the progress of photoconversion. This reaction is initiated by a saturating R-laser pulse of 648.5 nm, establishing an equilibrium of the photochromic system between P_r and the very early intermediates, Iⁱ₇₀₀ (P_rφ Iⁱ₇₀₀)- The decay of Iⁱ₇₀₀ as well as the formation of P_fr was recorded by the application of a second pulse varied between 698 and 717.5 nm, which inhibits the formation of P_lr being absorbed predominantly by Iⁱ₇₀₀or P_fr, respectively. The most effective inhibition for the second pulse is found up to 10 u.s after the first pulse and this is interpreted by photoreversion of Iⁱ₇₀₀ to P_r; thus reducing the formation of P_fr from Iⁱ₇₀₀. This early inhibition decreases between 10 μs to 100 ms after the R-laser pulse, as a result of the decay of Iⁱ_bl to a bleached species I,;. This decay can be described by three first order kinetics with the rate constants k₁₂= 16830 ± 2970 s^-1, k₁₂= 666 ± 218 s^-1,k₁₃= 9.8 ± 0.9 s^-1. A second inhibition, due to the formation of P_fr, is found for dark intervals <100 ms and can be described by two first order kinetics with the rate constants k₂₁= 2.9 ± 0.6 s^-1 and k₂₂= 0.17 s^-l.     

Experimental versus theoretical evidence for the rate‐limiting steps in uncatalyzed and H+‐ and HO−‐catalyzed hydrolysis of the amide bond

Recent theoretical studies of the alkaline hydrolysis of the amide bond have indicated that the nucleophilic attack of the hydroxide ion at the carbonyl carbon of the amide group is rate limiting. This is shown to be inconsistent with a large amount of experimental observations where the expulsion of the leaving group has been shown to be rate limiting. A kinetic approach has been described, which allows us to diagnose whether the pH‐independent/uncatalyzed hydrolysis of amides involves (a) both the uncatalyzed water reaction (k_w) and H⁺‐ (k_H) and HO^?‐catalyzed (k_OH) water reaction, (b) only the k_w reaction, or (c) only the k + k_OH reaction. The analysis described in this critical review does not favor the recent theoretical claims of the absence of the water reaction in the pH‐independent/uncatalyzed hydrolysis of formamide and urea. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 599–611, 2009     

Reaction kinetics of hydrated electrons in a quaternary micro emulsion system: A pulse radiolysis study

The pulse-radiolysis technique has been employed to produce and study the kinetics of hydrated electrons (e_aq⁻) in a quaternary micro emulsion (Sodium Lauryl Sulfate (NaLS)/water/cyclohexane/1-pentanol) system. Two orders of magnitude higher life time (20 μs) of the e_aq⁻ has been obtained as compared to that in reverse micelles reported earlier. Several probes including a biomolecule have been used to determine the water pool concentrations and quenching constants (k_q). The observed yield and half life (t_1/2) of the hydrated electrons vary smoothly as the water droplet sizes are changed. The bimolecular rate constants for the reaction of e_aq⁻ with different solutes have been determined. It has been observed that the measured bimolecular rate constants for the reaction of hydrated electrons with different solutes are indicative of the solubilization sites, the water core sizes, and the surrounding environment. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 699–705, 1998     

Reactivity Trends and Kinetic Inspection of Hydroxide Ion Attack and DNA Interaction on Some Pharmacologically Active Agents of Fe(II) Amino Acid Schiff Base Complexes at Different Temperatures

The reactivity of few novel high‐spin Fe(II) complexes of Schiff base ligands derived from 2‐hydroxynaphthaldehyde and some variety of amino acids with the OH^? ion has been examined in an aqueous mixture at the temperature range from 10 to 40°C. Based on the kinetic investigations, the rate law and a plausible mechanism were proposed and discussed. The general rate equation was suggested as follows: rate = k_obs[complex], where k_obs. = k₁ + k₂[OH^?]. Base‐catalyzed hydrolysis kinetic measurements imply pseudo–first‐order doubly stage rates due the presence of mer‐ and fac‐isomers. The observed rate constants k_obs are correlated with the effect of substituent R in the structure of the ligands. From the effect of temperature on the rate base hydrolysis reaction, various thermodynamic parameters were evaluated. The evaluated rate constants and activation parameters are in a good agreement with the stability constants of the investigated complexes. Moreover, the reactivity of the investigated complexes toward DNA was examined and found to be in a good agreement with the reported binding constants.     

Reactions of Group 3 Metal Alkyls in the Gas Phase. Part 10: The addition of olefins to the monomeric diisobutylaluminiumhydride

The relative rate constants for adding ethylene (k₁), propylene (k₂) and 2-methyl-but-1-ene (k₃) to gaseous diisobutylaluminium hydride produced in situ from AlⁱBu₃ have been measured in the temperature range 104–169° in the presence of an excess of equimolar olefin mixtures. The following temperature dependences of the relative rate constants have been obtained: Two compensating factors determine the rate of addition of olefins to Al? H and Al? C bonds: (a) the steric effect, reflected in the differences in the preexponential factors and (b) the polar effects, reflected in differences in the activation energies. In the addition of olefins to R₂Al? H bonds in contrast to R₂Al? C bonds, the steric effect (a) does not always overrule the opposing energy effect. At temperatures below 125° e.g., isobutene adds slightly faster to HAlⁱBu₂, than ethylene. These results are in perfect agreement with expectations based on a reaction mechanism involving a tight asymmetric quadrupolar 4-centre transition state similar to that postulated earlier for the addition of olefins to Al? C bonds.     

Kinetics and mechanism of pyrogallol autoxidation: Calibration of the dynamic response of an oxygen electrode

The kinetics of the reaction between 1,2,3-trihydroxybenzene (pyrogallol) and O₂ (autoxidation) have been determined by monitoring the concentration of dissolved dioxygen with a polarographic oxygen electrode. The reaction is carried out in pseudo-first-order excess pyrogallol, 25°C, 0.08 M NaCl, and 0.04 M phosphate buffer in the pH range 6.9–10.5. Data collection precedes reaction initiation, but only the data recorded after the estimated 3.2 s dead time are used in kinetics calculations. Observed rate constants are corrected for incomplete mixing, which is treated as a first-order process that has an experimentally determined mixing rate constant of 4.0 s^?1. The rate law for the reaction is ?d[O₂]/dt=k_app[PYR]_tot[O₂], in which [PYR]_tot is the total stoichiometric pyrogallol concentration. A mechanism is presented which explains the increase in rate with increasing [OH^?] by postulating that H₂PYR^? (k₂) has greater reactivity with dissolved dioxygen than does H₃PYR (k₁). The data best fit the equation k_app=(k₁ + k₂K_H[OH^?])/(1 + K_H[OH^?]) when the value of the hydrolysis constant K_H (the quotient of the pyrogallol acid dissociation and water autoprotolysis constants) for this medium equals 3.1×10⁴ M^?1. The resulting values of k₁ and k₂, respectively, equal (0.13 + 0.01) M^?1 s^?1 and (3.5 plusmn; 0.1) M^?1 s^?1. This reaction is recommended as a test reaction for calibrating the dynamic response of an O₂-electrode. © 1993 John Wiley & Sons, Inc.     

Kinetic evidence for the occurrence of general acid-base catalysis in N-methylhydroxylaminolysis of N-ethoxycarbonylphthalimide (NCPH)

Pseudo-first-order rate constants (k_{1 obs}) for the reaction of MeNHOH with NCPH obey the relationship: k_{1 obs}=k^′_b[MeNHOH]_T² where [MeNHOH]_T represents total concentration of N-methylhydroxylamine buffer. The rate constants, k_{1 obs} obtained at different total concentration of acetate buffer ([Buf]_T) in the presence of 0.004 mol dm⁻³ MeNHOH follow the relationship: k_{1 obs}=k_b[Buf]_T. The values of acetate buffer-catalyzed rate constant (k_b) at different pH reveal the occurrence of both general base- and general acid- or general base-specific acid-catalysis in the reaction of MeNHOH with NCPH. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 647–654, 1997.     

The Role of Solvation in the Kinetics and the Mechanism of Hydroperoxide Radicals Addition to π‐Bonds of 1,2‐Diphenylethylene and 1,4‐Diphenylbutadiene‐1,3

A combination of microcalorimetry, the rotating sector method, and ESR at 323 K in the environment of 10 solvents of different polarities was used to measure rate constants of addition of hydroperoxide radicals () to π bonds of trans‐1,2‐diphenylethylene and trans,trans‐1,4‐diphenylbutadiene‐1,3 (k₂) and disproportionation rate constants of these radicals (k₃). With increasing dielectric constant of the medium, k₂ values increase from 69 to 410 M⁻¹ · s⁻¹, and k₃ values almost do not change and are in the range of (1.0 ± 0.2) × 10⁸ M⁻¹ · s⁻¹. A linear dependence of logarithm values of rate constants from the dielectric constant of the medium in the coordinates of the Kirkwood–Onsager equation was found that allows to make a conclusion about the effect of nonspecific solvation in the studied systems. The quantum‐chemical analysis (NWChem, DFT B3LYP/6‐311G**) of the detailed mechanism for addition shows that the influence of the medium polarity reflects the superposition of the effects of nonspecific and specific solvation. The scale of the polar effect will depend on how different solvation energies of the transition and the initial reaction complexes. If a value of the solvation energy of the transition complex is larger than the solvation energy of the initial reaction complex, then the reaction rate should increase with an increase of the solvent's polarity and decrease otherwise.     

High‐Temperature Rate Constants for H + Tetramethylsilane and H + Silane and Implications about Structure–Activity Relationships for Silanes

The shock‐tube technique has been used to investigate the reactions H + SiH₄ → H₂ + SiH₃ (R1) and H + Si(CH₃)₄ → Si(CH₃)₃CH₂ + H₂ (R2) behind reflected shock waves. C₂H₅I was used as a thermal in situ source for H atoms. For reaction (R1), the experiments covered a temperature range of 1170–1251 K and for (R2) 1227–1320 K. In both cases, the pressures were near 1.5 bar. In these experiments, H atoms were monitored with atomic resonance absorption spectrometry. Fits to the H‐atom temporal concentration profiles applying postulated chemical kinetic reaction mechanisms were used for determining the rate constants k₁ and k₂. Experimental rate constants were well represented by the Arrhenius equations k₁(T) = 2.75 × 10⁻⁹ exp(−37.78 kJ mol⁻¹/RT) cm³ s⁻¹ and k₂(T) = 1.17 × 10⁻⁷ exp(−86.82 kJ mol⁻¹/RT) cm³ s⁻¹. Transition state theory (TST) calculations based on CBS‐QB3 and G4 levels of theory show good agreement with experimentally obtained rate constants; the experimental values for k₁ and k₂ are ∼40% lower and ∼50% larger than theoretical predictions, respectively. For the development of a mechanism describing the thermal decomposition of tetramethylsilane (Si(CH₃)₄; TMS), also TST‐based rate constants for reaction CH₃ + Si(CH₃)₄ → Si(CH₃)₃CH₂ + CH₄ (R3) were calculated. A comparison between experimental and theoretical rate constants k₂ and k₃ with available rate constants from the literature indicates that Si(CH₃)₄ has very similar reactivity toward H abstractions like neopentane (C(CH₃)₄), which is the analog hydrocarbon to TMS. Based on these results, the possibility of drawing reactivity analogies between hydrocarbons and structurally similar silicon‐organic compounds for H‐atom abstractions is discussed.     

Role of the supramolecular structure of the reactants in the kinetics of the liquid-phase synthesis and decomposition of explosives

Formulas relating the observed rate constant of the initial reaction step (k _ef) to the rate constants of the elementary steps (k _i ), to the monomer-association species equilibrium constants (K _i ), and to the concentrations of the reactants (A _i ) and solvent have been obtained for a number of simple kinetic models of liquid-phase explosive material synthesis and decomposition reactions involving associating reactants. The k _ef = F(k _i , K _i , and A _i ) relationship is independent of the rate law of the reaction and is governed by the association species type (autoassociation or heteroassociation species) and by the number of association species kinds. In the case of parallel reactions involving association species, as distinct from the same reactions involving unassociated reactants, concentration variations have an effect on the ratio of the rates of the parallel steps and on the product yield ratio. By varying the reaction temperature, it is possible to make the rates of the parallel steps to vary in opposite ways. When monomers, dimers, and tetramers are present in the reaction mixture, the temperature dependence of lnk _ef may have an extremum. These deduced regularities are in qualitative agreement with experimental data.     

The microenvironmental effects of helical conformations of amylose: 9. Catalytic effects of amylose on the hydrolysis of p-substituted phenol esters and structural effects of substrates

Hydrolytic rate constants of p-substituted phenol esters of carboxylic acids with various chain lengths were measured in 1:1 (v/v) Me₂SO-H₂O. Amylose accelerates the hydrolytic rates of all substrates, but the catalytic patterns are different for long and short chain substrates, i.e., acetates (2-X) show 2nd order kinetics, dodecanoates, (12-X) and hexadecanoates (16-X) follow Michaelis-Menten saturation kinetics. The dissociation constants K_d of inclusion complexes are dependent on the chain length of substrates. The rate constants k_un, K_obs, k₂ and k_o of 12-X and 2-X conform to the Hammett relation, the ρ values are almost the same, whether in the presence or absence of amylose. But k_un, k_obs and k_c values of 16-X all cannot be correlated by the Hammett equation because of the aggregation and self-coiling of 16-X in this poor solvent. Thermodynamic parameters ΔH_i and ΔS_i of the inclusion process and activation parameters ΔH_c^≠ and ΔS_c^≠ were obtained from the temperature dependence of K_d and k_c. The results indicate that the formation of inclusion complexes between amylose and substrates is an entropy disfavored and enthalpy favored process. Comparison of ΔH_c^≠, ΔS_c^≠ with ΔH_un^≠ and ΔS_un^≠ shows that the acceleration of hydrolysis of long chain substrates by amylose is caused by the formation of helical inclusion complexes.     

Formation of nitrosothiols by the reaction of different forms of hemoglobin with (tetranitrosyl)bis(pyrimidin-2-ylthio)diiron

The reaction of hemoglobin (Hb), oxyhemoglobin (HbO₂), and methemoglobin (metHb) with the tetranitrosyl iron complex of the fu₂-S type [Fe₂(SC₄H₃N₂)₂(NO)₄] (1) was studied. The reaction results in the nitrosylation of the free SH group of 93-β-cysteine in these forms of hemoglobin. The change in the Hb, HbO₂, and metHb concentrations was monitored by spectrophotometry, recording the difference absorption spectra of the experimental systems with these forms of hemoglobin and the buffer containing complex 1 in the same concentration. The absorption spectra were processed to obtain the components using the MATHCAD method. The nitrosothiol concentration was determined by the Saville reaction. In a protic medium containing 3.3% DMSO, complex 1 spontaneously generates NO due to hydrolysis (k = 3.7 · 10^-4 s^-1). Oxyhemoglobin reacts with evolved NO to form metHb. Complex 1 reduces metHb with a high rate to yield Hb (k = 6.7 · 10^-3 s^-1) followed by the formation of HbNO (k = 6.5 · 10^-3 s^-1). Oxidized complex 1 yields NO with a higher rate than the starting complex does. The reaction of HbO₂ and metHb (0.02 mmo1 L^-1) with complex 1 affords nitrosothiols in micromolar concentration during 5 min, and no nitrosothiol is formed in the case of Hb.     

Kinetic study on acid‐base catalyzed hydrolysis of azimsulfuron,a sulfonylurea herbicide

Pseudo‐first‐order rate constants (k_obs) for hydrolysis of a sulfonylurea herbicide, azimsulfuron, AZIM®, {N‐[[(4,6‐dimethoxy‐2‐pyrimidinyl)amino]carbony]‐1‐methyl‐4‐(2‐methyl‐2H‐tetrazol‐5‐yl)‐1H‐pyrazole‐5‐sulfonamide} (AZS) follow an empirical relationship: k_obs =α₁ + α₂[⁻OH] + α₃[⁻OH]² within the [NaOH] range of 0.1–2.0 M at different temperatures ranging from 40 to 55°C. The contribution of α₃[⁻OH]² term is small compared with α₂[⁻OH] term and this turns out to be zero at 60°C. Pseudo‐first‐order rate constants (k_obs) for hydrolysis of AZS within the [H⁺] range from 2.5 × 10⁻⁶ to 1.4 M follow the relationship: k_obs = (α₁K _a + B₁[H⁺] + B₂[H⁺]²)/([H⁺] + K_a) where pK_a = 4.37 at 50°C. The value of B₁ is nearly 25 times larger than that of α₁. The rate of alkaline hydrolysis of AZIM is weakly sensitive to ionic strength. © 1999 John Wiley & Sons, Inc., Int J Chem Kinet 31: 253–260, 1999     

Photoinitiation. V. Effect of medium polarity on the acrylonitrile polymerization photoinitiated by naphthalene

The heterogeneous polymerization of acrylonitrile photoinitiated by naphthalene is influenced by the polarity of the reaction medium. The rate of initiation increases with the increasing dielectric strength of the reaction medium. A similar trend is observable for Stern–Volmer constants of naphthalene fluorescence quenching by acrylonitrile. The ratio k_p/k_t^1/2 of the rate constant for propagation and termination reactions is not influenced by a change in the polarity of the reaction medium. The effect of viscosity on the value of k_p/k_t^1/2 known for polymerization in a homogeneous medium was not observed in the reaction systems studied.     

Reaction Kinetics of Carbon Dioxide (CO2) Absorption in Sodium Salts of Taurine and Proline Using a Stopped‐Flow Technique

The pseudo–first‐order reaction rate constants (k₀, s^?1) for the reaction of carbon dioxide in aqueous solutions of sodium taurate (NaTau) and sodium prolinate (NaPr) were measured using a stopped‐flow technique at a temperature range of 298–313 K. The solutions concentration varied from 5 to 50 mol m^?3 and from 4 to 12 mol m^?3 for NaTau and NaPr, respectively. Comparing the k₀ values, aqueous NaPr was found to react very fast with CO₂ as compared with the industrial standard aqueous monoethanolamine (MEA) and aqueous sodium taurate (NaTau) was found to react slower than aqueous MEA at the concentration range considered in this work. For the studied amino acid salts, the order of the reactions was found to be unity with respect to the amino acid salt concentration. Proposed reaction mechanisms such as termolecular and zwitterion reaction mechanisms for the reaction of CO₂ with aqueous solutions were used for calculating the second‐order reaction rate constants (k₂, m³ mol^?1 s^?1). The formation of zwitterion during the reaction with CO₂ was found to be the rate‐determining step, and the deprotonation of zwitterion was instantaneous compared to the reverse reaction of zwitterion to form an amino acid salt. The contribution of water was established to be significant for the deprotonation of zwitterion. Comparing the pseudo–first‐order reaction rate constants (k₀, s^?1) of various amino acid salts with CO₂, NaPr was found to be the faster reacting amino acid salt. The activation energy for NaTau was found to be 48.1 kJ mol^?1 and that of the NaPr was found to be 12 kJ mol^?1. The Arrhenius expressions for the reaction between CO₂ and the studied amino acid salts are