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Sharma A, Gupta VK, Reva I. Methoxyacetone revisited. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 308:123651. [PMID: 38056186 DOI: 10.1016/j.saa.2023.123651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/10/2023] [Accepted: 11/12/2023] [Indexed: 12/08/2023]
Abstract
Conformational space of methoxyacetone (MA) was studied at the MP2/6-311++G(d,p) and DFT(B3LYP)/6-311++G(d,p) levels of theory. Computations predict MA to adopt four conformations, resulting from internal rotations around the O=C-C-O (Trans, Cis) and C-C-O-C (trans, gauche) dihedral angles. The Tt (Trans-trans) conformer is the most stable. The computed energies of two gauche (Tg and Cg) conformers fall in the 3-8 kJ mol-1 range above Tt and should account for 1/3 of the room-temperature gas-phase equilibrium. The energy of Ct form is 11 kJ mol-1 above Tt, and its expected population is negligible (below 1 %). In our earlier work, MA monomers were isolated in cryogenic argon matrices and characterized by infrared spectroscopy. In the experiment, only the most stable Tt conformer was detected in the sample. Signatures of the other conformers were not detected, either in freshly deposited samples, or in samples subjected to different UV irradiations. We rationalize those observations in terms of computed barriers for intramolecular torsions, indicating occurrence of conformational cooling during deposition. The experimental infrared spectrum of the Tt form is now assigned with the aid of anharmonic DFT computations. Exposure of MA to UV irradiation in the 300-260 nm range led to photolysis, according to the Norrish type II mechanism, resulting in dimer between enol acetone and formaldehyde observed as a cage-confined intermediate photoproduct. The subsequent photolysis resulted in the formation of carbon monoxide as the dominating photoproduct, formed in the Norrish type I photoreaction. Mechanistic interpretation of this photo decarbonylation reaction is presented.
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Affiliation(s)
- Archna Sharma
- PG Department of Physics, University of Jammu, Jammu, J&K 180006, India
| | - Vivek K Gupta
- PG Department of Physics, University of Jammu, Jammu, J&K 180006, India
| | - Igor Reva
- CIEPQPF, Department of Chemical Engineering, Rua Sílvio Lima, University of Coimbra, Coimbra 3030-790, Portugal.
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Mihrin D, Andersen J, Jakobsen PW, Wugt Larsen R. Highly localized H 2O librational motion as a far-infrared spectroscopic probe for microsolvation of organic molecules. Phys Chem Chem Phys 2019; 21:1717-1723. [PMID: 30623967 DOI: 10.1039/c8cp05985c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The most prominent spectroscopic observable for the hydrogen bonding between individual molecules in liquid water is the broad absorption band detected in the spectral region between 300 and 900 cm-1. The present work demonstrates how the associated large-amplitude out-of-plane OH librational motion of H2O molecules also directly reflects the microsolvation of organic compounds. This highly localized OH librational motion of the first solvating H2O molecule causes a significant change of dipole moment and gives rise to a strong characteristic band in the far-infrared spectral region, which is correlated quantitatively with the complexation energy. The out-of-plane OH librational band origins ranging from 324.5 to 658.9 cm-1 have been assigned experimentally for a series of four binary hydrogen-bonded H2O complexes embedded in solid neon involving S-, O- and N-containing compounds with increasing hydrogen bond acceptor capability. The hydrogen bond energies for altogether eight binary H2O complexes relative to the experimental value of 13.2 ± 0.12 kJ mol-1 for the prototypical (H2O)2 system [Rocher-Casterline et al., J. Chem. Phys., 2011, 134, 211101] are revealed directly by these far-infrared spectroscopic observables. The far-infrared spectral signatures are able to capture even minor differences in the hydrogen bond acceptor capability of O atoms with slightly different alkyl substituents in the order H-O-C(CH3)3 > CH3-O-CH3 > H-O-CH(CH3)2 > H-O-CH2CH3.
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Affiliation(s)
- D Mihrin
- Department of Chemistry, Technical University of Denmark, Kemitorvet 206, 2800 Kgs. Lyngby, Denmark.
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Ali OY, Jewer E, Fridgen TD. Infrared spectroscopic characterization of hydrogen-bonded propylene oxide − ethanol and propylene oxide − 2-fluoroethanol complexes isolated in solid neon matrices. CAN J CHEM 2013. [DOI: 10.1139/cjc-2013-0355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The infrared absorption spectra of hydrogen-bonded complexes of propylene oxide with either ethanol or 2-fluoroethanol have been recorded in neon matrices. Mixtures of propylene oxide and ethanol or propylene oxide and 2-fluoroethanol vapors were mixed with an excess of neon gas and deposited onto a KBr substrate at 4.2 K. The results indicate that hydrogen-bonded complexes were formed with propylene oxide as the hydrogen bond acceptor and either ethanol or 2-fluoroethanol as the hydrogen bond donors. The features assigned to the O−H stretch were red-shifted by 175 and 193 cm−1 for the ethanol- and 2-fluoroethanol-containing complexes, respectively. The difference in red shifts can be accounted for due to the greater acidity of 2-fluroethanol. Deuterium isotope experiments were conducted to help confirm the assignment of the O–H stretch for the complexes. As well, structures and infrared spectra were calculated using B3LYP/6-311++G(2d,2p) calculations and were used to compare with the experimental spectra. A “scaling equation” rather than a scaling factor was used and is shown to greatly increase the utility of the calculations when comparing with experimental spectra. An examination of the O–H stretching red shifts for many hydrogen-bound complexes reveals a relationship between the shift and the difference between the acidity of the hydrogen bond donor and the basicity of the hydrogen bond acceptor (the enthalpy of proton transfer). Both hydrogen-bonded complexes and proton-bound complexes appear to have a maximum in the reduced frequency value that corresponds to complexes where the hydrogen/proton are equally shared between the two bases.
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Affiliation(s)
- Osama Y. Ali
- Department of Chemistry, Memorial University, St. John’s, NL A1B 3X7, Canada
| | - Elyse Jewer
- Department of Chemistry, Memorial University, St. John’s, NL A1B 3X7, Canada
| | - Travis D. Fridgen
- Department of Chemistry, Memorial University, St. John’s, NL A1B 3X7, Canada
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Chao MC, Weng NH, Chang HC, Jiang JC, Lin SH. High-Pressure and Concentration-Dependent Studies on C-H-O Interactions of Binary Aqueous Mixtures: Formic Acid/D2O and Acetone/D2O. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200100090] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chandra AK, Zeegers-Huyskens T. A theoretical investigation of the interaction between substituted carbonyl derivatives and water: Open or cyclic complexes? J Comput Chem 2012; 33:1131-41. [PMID: 22344933 DOI: 10.1002/jcc.22943] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/17/2011] [Accepted: 01/08/2012] [Indexed: 02/06/2023]
Affiliation(s)
- Asit K Chandra
- Department of Chemistry, North Eastern Hill University, Shillong 793022, India.
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On the possible catalytic role of a single water molecule in the acetone + OH gas phase reaction: a theoretical pseudo-second-order kinetics study. Theor Chem Acc 2011. [DOI: 10.1007/s00214-011-0921-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Silva PL, Bastos EL, El Seoud OA. Solvation in Binary Mixtures of Water and Polar Aprotic Solvents: Theoretical Calculations of the Concentrations of Solvent−Water Hydrogen-Bonded Species and Application to Thermosolvatochromism of Polarity Probes. J Phys Chem B 2007; 111:6173-80. [PMID: 17503801 DOI: 10.1021/jp068596l] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermo-solvatochromism of two polarity probes, 2,6-diphenyl-4-(2,4,6-triphenyl- pyridinium-1-yl)phenolate, RB, and 2,6-dichloro-4-(2,4,6-triphenylpyridinium-1-yl) phenolate, WB, in aqueous acetone, Me2CO, and aqueous dimethylsulfoxide, DMSO, has been studied. The data obtained have been analyzed according to a recently introduced solvation model that explicitly considers the presence of 1:1 organic solvent-water hydrogen-bonded species, S-W, in the bulk binary mixture and its exchange equilibria with (S) and (W) in the solvation shell of the probe. Calculations require reliable values of Kdissoc, the dissociation constant of S-W. Previously, this has been calculated from the dependence of the densities of binary solvent mixtures on their composition. Using iteration, the volume of the hydrogen-bonded species, VS-W, and Kdissoc were obtained simultaneously from the same set of experimental data. This approach may be potentially suspect because Kdissoc, and VS-W are highly correlated. Therefore, we extended a recently introduced approach for the calculation of Valcohol-W to binary mixtures of water with acetone, acetonitrile, N,N-dimethylformamide, DMSO, and pyridine. This approach includes: Determination of VS-W from ab initio calculations by the COSMO solvation model; correction of these volumes for the nonideal behavior of the binary solvent mixtures at different temperatures; use of corrected VS-W as a constant (not an adjustable parameter) in the equation that is employed to calculate Kdissoc (from density versus binary solvent composition). Solvation of RB and WB by Me2CO-W showed different behavior from that of aqueous DMSO. Thus, water is able to displace Me2CO more efficiently than DMSO from the probe solvation shell. Me2CO-W and DMSO-W displace their corresponding precursor solvents; this is more efficient for the former case because the strong DMSO-W interactions attenuate the solvation capacity of this species. Temperature increase resulted in desolvation of both probes, due to concomitant decrease of the structures of the component solvents.
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Affiliation(s)
- Priscilla L Silva
- Instituto de Química, Universidade de São Paulo, C.P. 26077, 05513-970 São Paulo, S.P., Brazil
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Bhakta R, Thomas R, Hipler F, Bettinger HF, Müller J, Ehrhart P, Devi A. MOCVD of TiO2thin films and studies on the nature of molecular mechanisms involved in the decomposition of [Ti(OPri)2(tbaoac)2]. ACTA ACUST UNITED AC 2004. [DOI: 10.1039/b405963h] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Macrae VA, Downs AJ. Matrix studies of the thermal and photolytic reactions of Ga vapour species with H2O: formation and characterisation of the adducts Ga·OH2and Ga2·OH2and the photoproducts HGaOH, GaOH and Ga(μ-H)(μ-OH)Ga. Phys Chem Chem Phys 2004. [DOI: 10.1039/b405298f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Chang HC, Jiang JC, Lin SH, Weng NH, Chao MC. Evidence for C–H–O interaction of acetone and deuterium oxide probed by high-pressure. J Chem Phys 2001. [DOI: 10.1063/1.1386914] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Wrobel R, Sander W, Kraka E, Cremer D. Reactions of Dimethyl Ether with Atomic Oxygen: A Matrix Isolation and a Quantum Chemical Study. J Phys Chem A 1999. [DOI: 10.1021/jp984631f] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roman Wrobel
- Lehrstuhl für Organische Chemie II der Ruhr-Universität, D-44780 Bochum, Germany, and Theoretical Chemistry, University of Göteborg, Reutersgatan 2, S-41320 Göteborg, Sweden
| | - Wolfram Sander
- Lehrstuhl für Organische Chemie II der Ruhr-Universität, D-44780 Bochum, Germany, and Theoretical Chemistry, University of Göteborg, Reutersgatan 2, S-41320 Göteborg, Sweden
| | - Elfi Kraka
- Lehrstuhl für Organische Chemie II der Ruhr-Universität, D-44780 Bochum, Germany, and Theoretical Chemistry, University of Göteborg, Reutersgatan 2, S-41320 Göteborg, Sweden
| | - Dieter Cremer
- Lehrstuhl für Organische Chemie II der Ruhr-Universität, D-44780 Bochum, Germany, and Theoretical Chemistry, University of Göteborg, Reutersgatan 2, S-41320 Göteborg, Sweden
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Mielke Z, Wierzejewska M, Olbert A, Krajewska M, Tokhadze KG. Matrix infrared spectra of nitrous acid complexes with some oxygen bases. J Mol Struct 1997. [DOI: 10.1016/s0022-2860(97)00201-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Han SW, Kim K. Infrared Matrix Isolation Study of Acetone and Methanol in Solid Argon. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp961538n] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sang Woo Han
- Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea
| | - Kwan Kim
- Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea
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Åstrand P, Karlström G, Engdahl A, Nelander B. Novel model for calculating the intermolecular part of the infrared spectrum for molecular complexes. J Chem Phys 1995. [DOI: 10.1063/1.468578] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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