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Goldschmidt, Heinrich; Udby, Olaf

doi:10.1515/zpch-1907-0140

Cited by 45 publications

(5 citation statements)

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“…This accounts for the H/D exchange; the ism is schematically illustrated in Figure 4. The computed barrier is E a = 0-20 1 in the range n = 1-4. formation. This has been discussed recently in a paper by Hansen et al 46 The o requirements that have to be fulfilled for efficient H/D exchange is a ally favourable mechanism for proton migration plus a sufficiently long-lived n complex.…”

Section: Biological Water Clustersmentioning

confidence: 99%

“…of acid-base reactions was propelled by Arrhenius' clear notion that a proton rather than a hydrogen atom is liberated from an acid upon the action of water: an extension of his theory that salts dissolve into ions in water that was presented in his 1884 doctoral thesis Recherches sur la conductivité galvanique des électrolytes (Investigations on the galvanic conductivity of electrolytes). Goldschmidt and Udby went further by proposing that the proton is attached to a water molecule, 1 in the form now known as the hydroxonium ion (also named hydronium or oxonium ion). The first experimental verification of the hydroxonium ion in the gas phase was made by Mann et al in 1940.…”

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confidence: 99%

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Proton Mobility in Water Clusters

Ryding

Andersson

Zatula

et al. 2012

Eur J Mass Spectrom (Chichester)

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Proton mobility in water occurs quickly according to the so-called Grotthuss mechanism. This process and its elementary reaction steps can be studied in great detail by applying suitable mass spectrometric methods to ionic water clusters. Careful choice of suitable core ions in combination with analysis of cluster size trends in hydrogen/deuterium isotope exchange rates allows for detailed insights into fascinating dynamical systems. Analysis of the experiments has been promoted by extensive and systematic quantum chemical model calculations. Detailed low-energy mechanistic pathways for efficient water rearrangement and proton transfer steps, in particular cases along short preformed "wires" of hydrogen bonds, have been identified in consistency with experimental findings.

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Section: Biological Water Clustersmentioning

confidence: 99%

mentioning

confidence: 99%

Proton Mobility in Water Clusters

Ryding

Andersson

Zatula

et al. 2012

Eur J Mass Spectrom (Chichester)

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“…Historically, it was Arrhenius who realized that it is a proton (rather than a hydrogen atom) that is liberated from an acid upon its interaction with water, whereas it was Goldschmidt and Udby who proposed that the liberated proton is attached to a water molecule in the form of H 3 O + , now known as the hydroxonium ion. [1] The first experimental verification of this idea was made in 1940 by Mann, using mass spectrometry. [2] Since then, a large number of studies of H 3 O + and its water adducts have been performed.…”

Section: Introductionmentioning

confidence: 99%

Insights into the dynamics of evaporation and proton migration in protonated water clusters from Large‐scale Born–Oppenheimer direct dynamics

et al. 2012

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Large-scale on-the-fly Born-Oppenheimer molecular dynamics simulations using recent advances in linear scaling electronic structure theory and trajectory integration techniques have been performed for protonated water clusters around the magic number (H(2)O)(n)H(+) , for n = 20 and 21. Besides demonstrating the feasibility and efficiency of the computational approach, the calculations reveal interesting dynamical details. Elimination of water molecules is found to be fast for both cluster sizes but rather insensitive to the initial geometry. The water molecules released acquire velocities compatible with thermal energies. The proton solvation shell changes between the well-known Eigen and Zundel motifs and is characterized by specific low-frequency vibrational modes, which have been quantified. The proton transfer mechanism largely resembles that of bulk water but one interesting variation was observed.

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“…We found that esterification as well as amination reactions are hydrogen ion catalyzed [12]. Therefore, the reaction rate is proportional to the hydroxyl or amino group concentration and to the square of the carboxyl group concentration.…”

Section: Resultsmentioning

confidence: 97%

Kinetics of Condensation Reactions between Ethanolamine (Amino-Alcohol) and Dicarboxylic Acids at 413 K

Patil

Kapadi

Hundiwale

et al. 2013

Int. J. Chem. Kinet.

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The kinetics of condensation polymerization reactions between amino‐alcohol and various dibasic acids ranging from oxalic acid (n = 0 number of –CH2 groups) to sebacic acid (n = 8) is studied at 413 K in an inert atmosphere, with a catalyst and ensuring removal of product water. All of the studied reactions are chemically identical, and their rates may differ only in so far as reactivity affected by molecular weight. Our analysis of the kinetic data reveals that all reactions obey third‐order kinetics, and the degree of polymerization increases even upto 20 h, if same stoichiometry for both the reactants is maintained. The velocity constants for the reactions were found to be in the order for the acids as succinic > oxalic > sebacic > adipic. The rates are also comparable to similar reactions of diols and diacids. The analysis further reveals that the chain length as well the structural characteristics of the reactant molecules govern the speed of the reaction. It seems that the proper conformations and structural geometry do play an important role in the collisional process of formation of products in a desired time. The probable implications of the results and analysis of these observations are discussed.

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Über Esterbildung

Cited by 45 publications

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Proton Mobility in Water Clusters

Proton Mobility in Water Clusters

Insights into the dynamics of evaporation and proton migration in protonated water clusters from Large‐scale Born–Oppenheimer direct dynamics

Kinetics of Condensation Reactions between Ethanolamine (Amino-Alcohol) and Dicarboxylic Acids at 413 K

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