Quantum-chemical study on reactions of isocyanates with linear methanol associates: VII. Effect of nonspecific solvation on the reaction of methyl isocyanate with linear methanol associates

Samuilov, A. Ya.; Balabanova, F. B.; Samuilov, Ya. D.; Коновалов, А. И.

doi:10.1134/s1070428013010053

Cited by 12 publications

(4 citation statements)

References 19 publications

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“…85 In the reaction of methyl isocyanate with methanol, an increased reactivity of methanol associates is also observed compared to the methanol monomer both in the gas phase and in solvents of various nature. 86 Exactly the same phenomenon is observed in the reactions of isocyanic acid with associates of ethylene glycol. 87…”

Section: Resultsmentioning

confidence: 57%

Reactivity of hydrogen-bonded complexes of water, methanol, phenol and methyl amine

Samuilov,

Samuilov

2023

New J. Chem.

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Section: Resultsmentioning

confidence: 57%

Reactivity of hydrogen-bonded complexes of water, methanol, phenol and methyl amine

Samuilov,

Samuilov

2023

New J. Chem.

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“…This Table 4. Thermodynamic parameters of activation of tautomerization of carbamate VI into azomethinenol VII in gas phase at 298 K: the non-catalytic and catalyzed by the methanol associates Ia-Ic ALCOHOL ASSOCIATES AS CATALYSTS OF TAUTOMERIC TRANSFORMATIONS has been shown for the alcohols reactions with alkyl- [23] and arylisocyanates [24] as well as isocyanic acid [25]; homo associates of phenol [26] and its mixed associates with methanol [27] are more reactive towards isocyanates than the monomeric alcohols; the same effect has been marked in the case of transesterification reactions [28]. The enhancement of reactivity upon association has been revealed for the hydrogen-bond complexes of amines: homo associates of amines [29] and their hetero associates with alcohols [30] are more reactive towards amides formation from esters as compared to the monomeric amines.…”

Section: Catalysis Of Carbamate-azomethinenol Tautomeric Transformatimentioning

confidence: 99%

Alcohol associates as catalysts of tautomeric transformations

et al. 2015

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The B3LYP/6-311++G(df,p) quantum-chemical simulation has revealed that linear associates of methanol catalyze the ketone-enol, nitro-aci-nitro, and carbamate-azomethinenol tautomeric transformations. All the reactions proceed via the coherent transition states. The catalytic effect is enhanced with the increased alcohol degree of association. The acid-base properties of methanol are changed similarly.

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“…[50] Moreover, the authors used the PCM solvation model to account for the influence of the reaction medium and found that the activation barriers are influenced by solvent polarity. [51] Besides Samuilov et al, also other researchers have compared reaction mechanisms with addition of the hydroxy group of the alcohol to the C=N and C=O bonds in isocyanates. Çoban and Konuklar [52] computed free energy profiles of bimolecular urethane formation in benzene based on B3LYP and PCM to compare the mechanisms shown in the upper parts of Figures 1 and 2, respectively.…”

Section: Introductionmentioning

confidence: 99%

Reaction Mechanisms and Rate Constants of Auto‐Catalytic Urethane Formation and Cleavage Reactions

et al. 2021

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The chemistry of urethanes plays a key role in important industrial processes. Although catalysts are often used, the study of the reactions without added catalysts provides the basis for a deeper understanding. For the non‐catalytic urethane formation and cleavage reactions, the dominating reaction mechanism has long been debated. To our knowledge, the reaction kinetics have not been predicted quantitatively so far. Therefore, we report a new computational study of urethane formation and cleavage reactions. To analyze various potential reaction mechanisms and to predict the reaction rate constants quantum chemistry and transition state theory were employed. For validation, experimental data from literature and from own experiments were used. Quantitative agreement of experiments and predictions could be demonstrated. The calculations confirm earlier assumptions that urethane formation reactions proceed via mechanisms where alcohol molecules act as auto‐catalysts. Our results show that it is essential to consider several transition states corresponding to different reaction orders to enable agreement with experimental observations. Urethane cleavage seems to be catalyzed by an isourethane, leading to an observed 2nd‐order dependence of the reaction rate on the urethane concentration. The results of our study support a deeper understanding of the reactions as well as a better description of reaction kinetics and will therefore help in catalyst development and process optimization.

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Quantum-chemical study on reactions of isocyanates with linear methanol associates: VII. Effect of nonspecific solvation on the reaction of methyl isocyanate with linear methanol associates

Cited by 12 publications

References 19 publications

Reactivity of hydrogen-bonded complexes of water, methanol, phenol and methyl amine

Reactivity of hydrogen-bonded complexes of water, methanol, phenol and methyl amine

Alcohol associates as catalysts of tautomeric transformations

Reaction Mechanisms and Rate Constants of Auto‐Catalytic Urethane Formation and Cleavage Reactions

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