Fermi resonance in rotational isomers of furfural

Ballester, Lourdes; Carrió, C.; Bertrán, José Fernández

doi:10.1016/0584-8539(72)80184-3

Cited by 17 publications

(7 citation statements)

References 14 publications

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“…The isomerization or so-called Fermi resonance can be also noticed at the area around 1365-1395 cm −1 , representing the C-H bond in the aldehyde group. In our case, this corresponds with slightly shifted peaks at 1369 and 1395 cm −1 , belonging to cis and trans isomers of furfural [36] (Figure 1a). Peaks at 1466 and 1570 cm −1 stand for two C=C bonds as part of an aromatic ring in the FF structure.…”

Section: Ftir Spectrum Of Furfural Levulinic Acid and Hydroxymethylfurfuralsupporting

confidence: 54%

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

et al. 2021

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Bio-based levulinic acid (LA), furfural (FF), and hydroxymethylfurfural (HMF) represent key chemical intermediates when biorefining biomass resources, i.e., either cellulose, glucose, hexoses, etc. (HMF/LA), or hemicellulose, xylose, and pentose (FF). Despite their importance, their online in situ detection by process analytical technologies (PATs), solubility, and its temperature dependence are seldom available. Herein, we report their solubility and temperature dependence by examining n-hexane, cyclohexane, benzene, toluene, 1,4-dioxane, diethyl ether, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, formic acid, n-butanol, n-propanol, ethanol, methanol, and water. These solvents were selected as they are the most common nonpolar, polar aprotic, and polar protic solvents. Fourier-transform infrared (FTIR) spectroscopy was applied as a fast, accurate, and sensitive method to the examined solutions or mixtures. The latter also enables operando monitoring of the investigated compounds in pressurized reactors. Selected temperatures investigated were chosen, as they are within typical operating ranges. The calculated thermodynamic data are vital for designing biorefinery process intensification, e.g., reaction yield optimization by selective compound extraction. In addition to extracting, upstream or downstream unit operations that can benefit from the results include dissolution, crystallization, and precipitation.

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Section: Ftir Spectrum Of Furfural Levulinic Acid and Hydroxymethylfurfuralsupporting

confidence: 54%

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

et al. 2021

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“…Previous vibrational Fermi resonance studies − have employed a variety of experimental and theoretical methods to extract Fermi resonance coupling information from molecular vibrational spectra. These include both infrared and Raman studies of systems in which isotopic substitution 5,7 and/or variations in phase, , solvent, ,,− temperature, ,,,, or pressure 7,10,14-17 have been used to alter the observed Fermi resonance shifts and intensity changes.…”

Section: Introductionmentioning

confidence: 99%

Pressure Dependent Vibrational Fermi Resonance in Liquid CH₃OH and CH₂Cl₂

Devendorf

Ben‐Amotz

1998

J. Phys. Chem. A

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The vibrational Fermi resonance of two liquids, methanol (CH3OH) and dichloromethane (CH2Cl2), is investigated by measuring changes in the position and intensity of Fermi-coupled Raman bands as a function of pressure, in a diamond anvil cell. The Fermi resonance of interest occurs in the 2900 cm-1 spectral region, where coupling between the CH symmetric stretch fundamental and a CH bend overtone gives rise to two prominent bands. The methanol results reveal a pressure induced transition through exact resonance at 1.25 GPa, where the two coupled states decompose into a pair of fully mixed hybrid bands. In dichloromethane, on the other hand, the two coupled states are driven farther apart and become less mixed with increasing pressure. The Fermi resonance coupling coefficient, W, is found to be constant in each liquid up to pressures exceeding 1 GPa (W ≈ 52.6 and 22.3 cm-1 in CH3OH and CH2Cl2, respectively). The anharmonic shift of the CH bend is about 10 cm-1 in both liquids, determined by comparing the frequencies of the fundamental and Fermi resonance corrected overtone. The results are compared with those of previous Fermi resonance studies using solvent, phase, isotope, temperature, and pressure variation. In addition to yielding a robust method for quantifying Fermi resonance, pressure variation is shown to offer a powerful aid to the resolution of spectral assignment ambiguities.

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“…Maleic anhydride or maleic acid cannot be ruled out either. The presence of furfural also explains the bands at 2843 and 2811 cm -1 assigned to the C-H bond of the aldehyde group of furfural [27,28,35]. The negative peaks at 3719, 3672 and 3605, cm -1 denote the perturbation of OH groups at the surface of the alumina by the chemisorption of different species.…”

Section: This Work 1303mentioning

confidence: 87%

“…The bands at 3125 and 3080 cm-1 arise from H-C stretching vibrations in C=C bonds, and therefore, they are compatible with the presence of furfural, MA and MAc and maleate species. The bands at 2843 and 2811 cm -1 are C-H stretching vibrations of aldehydic group of furfural[27,28,35]. The bands at 2980 and 2942 cm -1 are typical of H-C stretching vibrations in C-C bonds, and therefore, they indicate the presence of other species different from any of those mentioned thus far because none of these species possess C-C bonds.…”

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confidence: 79%

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Gas phase oxidation of furfural to maleic anhydride on V 2 O 5 /γ-Al 2 O 3 catalysts: Reaction conditions to slow down the deactivation

Alonso-Fagúndez

Ojeda

Mariscal

et al. 2017

Journal of Catalysis

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An alumina-supported vanadium oxide catalyst (13.9 wt. % of vanadium oxide) has been tested on the gas phase oxidation of furfural and characterised by different techniques. These studies have showed that catalyst unavoidably deactivates by deposition of maleates and resins over the surface. Full regeneration is accomplished by burning off these deposits at 773 K. The studies have also demonstrated that if the primary contact occurs at temperatures at which furfural conversion is low and then the temperature is increased in a low to high temperature mode, an intense deposition of maleates and resins takes place and the catalyst is rapidly deactivated. The increasing of the temperatures does not result in removal of deposits but accelerates the deposition. Under this protocol the yield of maleic anhydride never exceeded 30 %, irrespective of the reaction conditions (temperature and O 2 /furfural mol ratio). On the contrary if the catalyst first contacts the reaction mixture at high oxidising potential, then the rate of maleate and resins deposition is much slower and so is the deactivation rate and the catalyst can display a higher yield of MA for longer period of time. A high oxidizing potential can be accomplished at high reaction temperature (close to full conversion). Higher oxidising potential 2 at a given high temperature can be accomplished by increasing the O 2 /furfural mol ratio. Thus, for example, first contacting the catalyst at 593 K (full conversion), 1 vol. % of furfural and an O 2 /furfural mol ratio = 10, maleic anhydride yield of 68 % was initially obtained and was still greater than 50 % after 15 h on stream. When contacting at 573 with 1 vol. % furfural and 29 vol. % of O 2 , the maleic anhydride yield was initially close to 75 % and above 60 after 15 h.

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Fermi resonance in rotational isomers of furfural

Cited by 17 publications

References 14 publications

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

Pressure Dependent Vibrational Fermi Resonance in Liquid CH₃OH and CH₂Cl₂

Gas phase oxidation of furfural to maleic anhydride on V 2 O 5 /γ-Al 2 O 3 catalysts: Reaction conditions to slow down the deactivation

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Fermi resonance in rotational isomers of furfural

Cited by 17 publications

References 14 publications

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

Solubility Temperature Dependence of Bio-Based Levulinic Acid, Furfural, and Hydroxymethylfurfural in Water, Nonpolar, Polar Aprotic and Protic Solvents

Pressure Dependent Vibrational Fermi Resonance in Liquid CH3OH and CH2Cl2

Gas phase oxidation of furfural to maleic anhydride on V 2 O 5 /γ-Al 2 O 3 catalysts: Reaction conditions to slow down the deactivation

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Pressure Dependent Vibrational Fermi Resonance in Liquid CH₃OH and CH₂Cl₂