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Győri T, Czakó G. A comprehensive benchmark ab initio survey of the stationary points and products of the OH· + CH 3OH system. J Chem Phys 2023; 158:034301. [PMID: 36681627 DOI: 10.1063/5.0133978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Reactions between methanol and the hydroxyl radical are of significant interest for combustion-, atmospheric-, and astrochemistry. While the two primary product channels (the formation of H2O with either CH3O· or ·CH2OH) have been the subject of numerous studies, the possibility of other products has seen little attention. Here, we present a comprehensive thermochemical survey of the stationary points and plausible products of the reaction, featuring 29 geometries optimized at the UCCSD(T)-F12b/aug-cc-pVTZ level, followed by accurate composite ab initio computations for all stationary points (including ·CH2OH dissociation and isomerization) and five product channels, with a detailed evaluation of basis set convergence and efficiency. The computations reveal that the formation of methanediol and the hydroxymethoxy radical is thermodynamically favorable and the endothermicity of formaldehyde formation is low enough to be a plausible product channel. We also observe unexpectedly large energy deviations between the partially-spin-adapted ROHF-RCCSD(T) method and ROHF-UCCSD(T) as well as between UHF-UCCSDT(Q) and ROHF-UCCSDT(Q) results.
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Affiliation(s)
- Tibor Győri
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary
| | - Gábor Czakó
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary
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2
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Chen YF, Chu LK. Infrared Characterization of Isotopic Analogues of Methanediol in Aqueous Solution. J Phys Chem A 2022; 126:5302-5309. [PMID: 35930362 DOI: 10.1021/acs.jpca.2c04008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dissolved methanediol in aqueous solution has been treated as the precursor for the formation of atmospheric formic acid in multiphase environments. In this work, methanediol, CH2(OH)2, and its isotopic analogues, CH2(OD)2, CD2(OH)2, and CD2(OD)2, in aqueous solution were prepared by dissolving paraformaldehyde and deuterium-substituted paraformaldehyde powders in H2O and D2O under reflux. Their infrared absorption contours of formaldehyde solutions at concentrations of <1 wt % are not dependent on the concentration, mainly referring to the characteristics of the monomeric configuration, and can be categorized into two parts. At wavenumbers >2000 cm-1, broad bands of moderate strengths were ascribed to the stretching modes of two OH or OD groups, observed at 3000-3700 and 2050-2750 cm-1, respectively. At wavenumbers of 950-1200 cm-1, the isotopic analogues of methanediols composed of CH2 moieties are featured with a singlet strong band at ca. 1030 cm-1, mainly attributed to the O-C-O stretching modes; the isotopic methanediols containing CD2 moieties manifested two intense bands at ca. 1100 and 980 cm-1, majorly enveloping the CD2 deformation and O-C-O stretching modes. The aforementioned spectral features were assigned on the basis of density functional theory, ωB97XD, with the basis set aug-cc-pVTZ and the solvent effect using the conductor-like polarizable continuum model. In addition, the predicted energetics suggested that the trans-methanediol is more stable than the cis- conformer by ca. 0.62 kcal mol-1 and majorly contributes to the infrared features. At higher concentrations of CH2(OH)2, extra bands at 920 and 1104 cm-1 appeared and were attributed to the C-O-C stretching modes of the dimeric/polymeric methanediol; that is, HO(CH2O)nH, n ≥ 2. These infrared characterizations of the isotopic analogues of methanediols provided suitable detection windows in the relevant atmospheric and aerosol reactions in the laboratory studies.
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Affiliation(s)
- Yi-Fang Chen
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300044, Taiwan
| | - Li-Kang Chu
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 300044, Taiwan
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Davis MC, Garrett NR, Fortenberry RC. Confirmation of gaseous methanediol from state-of-the-art theoretical rovibrational characterization. Phys Chem Chem Phys 2022; 24:18552-18558. [PMID: 35904881 DOI: 10.1039/d2cp02076a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-level rovibrational characterization of methanediol, the simplest geminal diol, using state-of-the-art, purely ab initio techniques unequivocally confirms previously reported gas phase preparation of this simplest geminal diol in its C2 conformation. The F12-TZ-cCR and F12-DZ-cCR quartic force fields (QFFs) utilized in this work are among the largest coupled cluster-based anharmonic frequencies computed to date, and they match the experimental band origins of the spectral features in the 980-1100 cm-1 range to within 3 cm-1, representing a significant improvement over previous studies. The simulated spectrum also matches the experimental spectrum in the strong Q branch feature and qualitative shape of the 980-1100 cm-1 region. Additionally, the full set of rotational constants, anharmonic vibrational frequencies, and quartic and sextic distortion constants are provided for both the lowest energy C2 conformer as well as the slightly higher Cs conformer. Several vibrational modes have intensities of 60 km mol-1 or higher, facilitating potential astronomical or atmospheric detection of methanediol or further identification in laboratory work especially now that gas phase synthesis of this molecule has been established.
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Affiliation(s)
- Megan C Davis
- Department of Chemistry & Biochemistry, University of Mississippi, University, MS, 38677-1848, USA.
| | - Noah R Garrett
- Department of Chemistry & Biochemistry, University of Mississippi, University, MS, 38677-1848, USA.
| | - Ryan C Fortenberry
- Department of Chemistry & Biochemistry, University of Mississippi, University, MS, 38677-1848, USA.
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Jian HY, Yang CT, Chu LK. Gaseous infrared spectra of the simplest geminal diol CH 2(OH) 2 and the isotopic analogues in the hydration of formaldehyde. Phys Chem Chem Phys 2021; 23:14699-14705. [PMID: 34190266 DOI: 10.1039/d1cp01354h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The infrared spectrum of the simplest geminal diol, methanediol or methylene glycol (CH2(OH)2), was successfully probed in the gaseous hydration of formaldehyde. The observed absorption bands coincided with the anharmonic vibrational wavenumbers predicted by B3LYP/aug-cc-pVTZ calculation. Based on the predicted rotational parameters and dipole derivatives, the simulated rovibrational contours of CH2(OH)2 agreed with the experimental spectrum, and the band origins of the OCO symmetric stretching mode (b-type) and the OCO asymmetric stretching mode (a-type) were determined to be 1027 and 1058 cm-1, respectively. In addition, the isotopic analogues, CD2(OH)2, CH2(OD)2, and CD2(OD)2, were also investigated. The band origins of the CD2 wagging mode (a-type) and the COH bending mode (a, c-type) of CD2(OH)2 were also determined to be 1121 and 1301 cm-1, respectively. The successful infrared characterization of gaseous methanediol makes it possible to directly investigate the relevant chemical reactions of geminal diols in atmosphere, astrophysics, and water-mediated reactions.
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Affiliation(s)
- Hung-Yang Jian
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd, Hsinchu 30013, Taiwan.
| | - Chih-Tsun Yang
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd, Hsinchu 30013, Taiwan.
| | - Li-Kang Chu
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd, Hsinchu 30013, Taiwan.
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Dwivedi S, Mata J, Mushrif SH, Chaffee AL, Tanksale A. Molecular Clustering in Formaldehyde-Methanol-Water Mixtures Revealed by High-Intensity, High-q Small-Angle Neutron Scattering. J Phys Chem Lett 2021; 12:480-486. [PMID: 33373259 DOI: 10.1021/acs.jpclett.0c03515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Methanol-Water (mw) mixtures, with or without a solute, display a nonideal thermodynamic behavior, typically attributed to the structure of the microphase. However, experimental observation of the microphase structures at the molecular length scale has been a challenge. We report the presence of molecular clusters in mw and formaldehyde-methanol-water (fmw) mixtures using small-angle neutron scattering (SANS) experiments and molecular dynamics (MD) simulations. Hydrophobic clusters of methanol in mw and formaldehyde-methanol in fmw mixtures were observed at low methanol compositions (xm ≤ 0.3). A three-dimensional hydrogen-bonded network of water with the solute is observed at xm = 0.5. Linear chains of methanol surrounding the formaldehyde and water molecules were observed at high methanol compositions (xm ≥ 0.7). The calculated size of the molecular clusters (r ≈ 0.5 nm, spherical) from the SANS data and their volume fraction closely matched the MD simulation results.
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Affiliation(s)
- Swarit Dwivedi
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jitendra Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Samir H Mushrif
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Alan L Chaffee
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Akshat Tanksale
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
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Parandaman A, Kumar M, Francisco JS, Sinha A. Organic Acid Formation from the Atmospheric Oxidation of Gem Diols: Reaction Mechanism, Energetics, and Rates. J Phys Chem A 2018; 122:6266-6276. [DOI: 10.1021/acs.jpca.8b01773] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Arathala Parandaman
- Department of Chemistry and Biochemistry, University of California—San Diego, La Jolla, California 92093, United States
| | - Manoj Kumar
- Department of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Joseph S. Francisco
- Department of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Amitabha Sinha
- Department of Chemistry and Biochemistry, University of California—San Diego, La Jolla, California 92093, United States
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Uddin N, Choi TH, Choi CH. Origin of Acid-Base Catalytic Effects on Formaldehyde Hydration. J Phys Chem A 2016; 120:9598-9606. [PMID: 27933907 DOI: 10.1021/acs.jpca.6b08783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanisms of hydronium- and hydroxide-catalyzed formaldehyde hydrations were investigated by quantum mechanical/molecular mechanical molecular dynamics in combination with flexible coordinates. A stepwise bimolecular and a concerted termolecular mechanism were found with a hydronium catalyst. The latter is more favorable and better consistent with experiment. Structurally, a dipole-bound species initially arranges the nucleophile in a favorable configuration for both routes, significantly enhancing the reactive collisions. On the one hand, the hydronium catalyst also plays a role of a reactant in the bimolecular path. On the other hand, only a stepwise mechanism was found with a hydroxide catalyst. Overall, hydroxide is a stronger catalyst than a hydronium when it is in contact distance with formaldehyde.
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Affiliation(s)
- Nizam Uddin
- Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University , Taegu 702-701, South Korea
| | - Tae Hoon Choi
- Department of Chemical Engineering Education, Chungnam National University , Daejeon 305-764, South Korea
| | - Cheol Ho Choi
- Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University , Taegu 702-701, South Korea
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Delcroix P, Pagliai M, Cardini G, Bégué D, Hanoune B. Identification of Di(oxymethylene)glycol in the Raman Spectrum of Formaldehyde Aqueous Solutions by ab Initio Molecular Dynamics Simulations and Quantum Chemistry Calculations. J Phys Chem A 2015; 119:9785-93. [PMID: 26352865 DOI: 10.1021/acs.jpca.5b06293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Di(oxymethylene)glycol forms in formaldehyde aqueous solutions by polymerization of methanediol. The structure and hydrogen bond interactions of di(oxymethylene)glycol with water were characterized by performing Car-Parrinello molecular dynamics simulations. The anharmonic vibrational frequencies of di(oxymethylene)glycol in solution were determined with ab initio calculations considering explicitly the hydrogen-bonded water molecules, while other interactions with solvent were described within a polarizable continuum model approach. The calculations allow for a detailed interpretation of the experimental Raman spectrum of formaldehyde aqueous solutions, leading to the assignment of the band at 920 cm(-1) to the symmetric CO stretching mode of di(oxymethylene)glycol.
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Affiliation(s)
- Pauline Delcroix
- Laboratoire de Physicochimie des Processus de Combustion et de l'Atmosphère, UMR 8522 CNRS/Université Lille 1 , F-59655 Villeneuve d'Ascq, France
| | - Marco Pagliai
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze , via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy
| | - Gianni Cardini
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze , via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy
| | - Didier Bégué
- Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254 CNRS-Equipe de Chimie Physique, Université de Pau et des Pays de l'Adour , 2 Avenue du Président Angot, 64053 Pau Cedex 9, France
| | - Benjamin Hanoune
- Laboratoire de Physicochimie des Processus de Combustion et de l'Atmosphère, UMR 8522 CNRS/Université Lille 1 , F-59655 Villeneuve d'Ascq, France
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Kumar M, Francisco JS. The Role of Catalysis in Alkanediol Decomposition: Implications for General Detection of Alkanediols and Their Formation in the Atmosphere. J Phys Chem A 2015; 119:9821-33. [DOI: 10.1021/acs.jpca.5b07642] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Manoj Kumar
- Department of Chemistry, University of Nebraska—Lincoln, 639 North 12th Street, Lincoln, Nebraska 68588, United States
| | - Joseph S. Francisco
- Department of Chemistry, University of Nebraska—Lincoln, 639 North 12th Street, Lincoln, Nebraska 68588, United States
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