Theoretical Study of the Isomerization of Maleic Acid Into Fumaric Acid

Ugarte, Ricardo; Bustos, Carlos; Moreno‐Villoslada, Ignacio

doi:10.4067/s0717-97072011000200007

Cited by 4 publications

(3 citation statements)

References 17 publications

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“…The thermal process requires high temperature (150–200 °C) and pressure (∼15.5 bar), whereas the catalytic process uses lower temperatures (30–130 °C). Thiourea is the most commonly used catalyst in the commercial process because of its low price, the low operating temperature (50–100 °C), and in contrast to acid catalysts, does not cause corrosion in reactors. − These facts lead to the reduction of operating costs.…”

Section: Introductionsupporting

confidence: 58%

Kinetic Modeling of Maleic Acid Isomerization to Fumaric Acid Catalyzed by Thiourea Determined by Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy

Lobo

Ortiz

Gonçalves

et al. 2020

Org. Process Res. Dev.

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Fumaric acid (FA) is an important commodity in the food and polymer industries; its main route of production is the chemical synthesis from maleic acid (MA). In this work, the isomerization of MA to FA catalyzed by thiourea was investigated. The experiments were performed in an automated reactor with temperature and stirring control, using methanol as the solvent to ensure a homogeneous system and to avoid a possible parallel hydration reaction to malic acid. The reaction kinetics was monitored in real time by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR/FT-IR). Studies on the influence of the catalyst concentration (1−20% of the initial molar concentration of MA) and the temperature (20−60 °C) were carried out in reaction times between 2 and 5 h. The kinetics of the reaction was modeled using an integral method over the infrared data, assuming a reaction mechanism that yielded a partial order of 1.41 for the MA concentration and a 0.99 order for the thiourea. These orders were similar to the ones found by the proposed mechanism for the acid-catalyzed isomerization, in which monomaleate is a nucleophilic reagent to react with the protonated MA. This may present a path for further studies regarding the correct reaction mechanism. The kinetic model provided an excellent correlation with the experimental data, and the observed activation energy of the reaction was calculated to be 43.1 kJ mol −1 . At higher temperatures, such as 60 °C, and with a thiourea concentration of 10% mol/mol (0.0502 mol L −1 ), the isomerization conversion was around 90% in 60 min. Accordingly, thiourea proved to be an appropriate catalyst for FA synthesis, and ATF/FT-IR proved to be a reliable technique for the kinetic study.

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Section: Introductionsupporting

confidence: 58%

Kinetic Modeling of Maleic Acid Isomerization to Fumaric Acid Catalyzed by Thiourea Determined by Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy

Lobo

Ortiz

Gonçalves

et al. 2020

Org. Process Res. Dev.

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“…Their crystalline structures have been reported long ago, − and the molecular structure of FA has been studied by both gas-phase electron diffraction and microwave spectroscopy. − In addition, the infrared (IR) and ultraviolet (UV) spectra of MA and FA in aqueous solution have been described, , as well as their room-temperature Raman spectra . The mechanism of thermal isomerization of MA into FA is a classic classroom example of a cis – trans isomerization and has been investigated early on. − …”

Section: Introductionmentioning

confidence: 99%

“… 26 The mechanism of thermal isomerization of MA into FA is a classic classroom example of a cis – trans isomerization and has been investigated early on. 27 − 31 …”

Section: Introductionmentioning

confidence: 99%

Matrix Isolation Study of Fumaric and Maleic Acids in Solid Nitrogen

2022

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Fumaric and maleic acids ((E)-and (Z)-HOOC− CHCH−COOH, FA and MA) were studied experimentally by infrared spectroscopy in nitrogen matrixes and theoretically by quantum chemical calculations. The calculations, carried out at the DFT(B3LYP) and MP2 levels of theory, predicted the existence of at least 5 conformers of maleic acid and 10 conformers of fumaric acid. After the deposition of the matrixes, two conformers of maleic acid (I and II) and three conformers (I−III) of fumaric acid were observed and characterized vibrationally. Selective narrowband near-infrared (NIR) excitation of the first OH stretching overtones of the different conformers of maleic and fumaric acids initially present in the matrixes allowed the generation of higher-energy forms, never before observed experimentally. In the case of maleic acid, conformers I (a cis−trans form, where cis and trans designate the conformation of the carboxylic groups of the molecule) and II (cis−cis) were found to generate the novel conformers VI (trans−trans) and VII (cis−trans), respectively. The conversion of conformer II into the most stable conformer I was also observed. For fumaric acid, the cis−cis conformers I−III were found to give rise to the new cis−trans conformers IV−VII, respectively. The tunneling decay of the new conformers produced upon NIR excitation of the lowest-energy conformers initially trapped in the matrixes was observed, and their lifetimes in solid N 2 were determined. The increased stability of all of the observed high-energy conformers of the studied acids in the N 2 matrix, compared to the argon matrix, where they could not be observed experimentally, demonstrates the stabilizing effect of the interaction between the OH groups of the acids with the matrix N 2 molecules, in line with previous observations for other carboxylic acids. In addition, the photochemistry of matrix-isolated maleic and fumaric acids upon broad-band UV irradiation (λ > 235 nm) was also investigated. UV-induced isomerization of both acids around the CC double bond was observed, together with their decarboxylation to acrylic acid.

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Interaction between glyphosate and mitochondrial succinate dehydrogenase

Ugarte

2014

Computational and Theoretical Chemistry

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Theoretical Study of the Isomerization of Maleic Acid Into Fumaric Acid

Cited by 4 publications

References 17 publications

Kinetic Modeling of Maleic Acid Isomerization to Fumaric Acid Catalyzed by Thiourea Determined by Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy

Kinetic Modeling of Maleic Acid Isomerization to Fumaric Acid Catalyzed by Thiourea Determined by Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy

Matrix Isolation Study of Fumaric and Maleic Acids in Solid Nitrogen

Interaction between glyphosate and mitochondrial succinate dehydrogenase

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