Standard free energy of the equilibrium between the trans-monomer and the cyclic-dimer of acetic acid in the gas phase from infrared spectroscopy

2015 ◽  
Vol 17 (11) ◽  
pp. 7477-7488 ◽  
Author(s):  
Manuel Goubet ◽  
Pascale Soulard ◽  
Olivier Pirali ◽  
Pierre Asselin ◽  
Florent Réal ◽  
...  
Keyword(s):  
Free Energy ◽  
Acetic Acid ◽  
Infrared Spectroscopy ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Standard Free Energy ◽  
Cyclic Dimer

The dimerization equilibrium of acetic acid in the gas phase at 298 K has been characterized from the analysis of jet-cooled and static cell infrared spectra supported by calculations.

scholarly journals Infrared Spectroscopic Characterization of CIT-6 and a Family of *BEA Zeolites

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sean R. Tomlinson ◽  
Tyler McGown ◽  
John R. Schlup ◽  
Jennifer L. Anthony
Keyword(s):  
Acetic Acid ◽  
Infrared Spectroscopy ◽  
Ion Exchange ◽  
Infrared Spectra ◽  
Local Structure ◽  
Far Infrared ◽  
Zinc Ion ◽  
Zeolite Beta ◽  
Acid Extraction ◽  
Structure Changes

Infrared spectroscopy is known to be a useful tool for identifying local structure changes in zeolites. Infrared spectroscopy is often employed to complement X-ray diffraction data. Local structure changes in zeolite CIT-6 and its zeolite beta (*BEA) analogs caused by calcination, altering framework composition, and ion exchange have been identified with mid- and far-infrared spectroscopy. Differences in the local structures of the samples were observed in mid- and far-infrared spectra, including changes in the intratetrahedral asymmetric stretch, the double-ring mode, and the intratetrahedral bending mode regions. The infrared spectra indicate that calcination or acetic acid extraction changed the structure of CIT-6 to that of zeolite beta (*BEA). Zinc ion exchange or the substitution of aluminum into the framework structure of acetic acid extracted samples retained the CIT-6 structure.

Infrared Studies of Ozone-Organosilicon Chemistries for SiO2 Deposition

1993 ◽  
Vol 334 ◽  
Author(s):  
J. A. Mucha ◽  
J. Washington
Keyword(s):  
Acetic Acid ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Gas Phase ◽  
Deposition Process ◽  
Dominant Factor ◽  
Ethoxy Group ◽  
Product Analysis ◽  
Infrared Studies ◽  
Hydride Elimination

AbstractGas-phase Fourier transform infrared spectroscopy has been used to monitor reactants and products in the study of O3 decomposition and the reaction of O3 with tetramethylsilane and tetraethoxysilane. The results confirm the interpretation that O3 decomposition is heterogeneous, and a dominant factor in SiO2 deposition using these chemistries. Product analysis shows that the higher reactivity of TEOS with O3 is probably due to the ability of TEOS to undergo α-hydride elimination of one ethoxy group, per molecule, and one oxidative acetic acid elimination, per molecule, during the deposition process. Results also suggest elimination via the Sicenter involving a single ethoxy group rather than via a 6-center elimination involving two ethoxy groups.

Prediction of Alkanolamine pKa Values by Combined Molecular Dynamics Free Energy Simulations and ab initio Calculations

2019 ◽  
Author(s):  
Javad Noroozi ◽  
William Smith
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Ab Initio Calculations ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Phase Reaction ◽  
Pka Values ◽  
Gas Phase Reaction ◽  
Reaction Free Energy ◽  
Energy Simulations

We use molecular dynamics free energy simulations in conjunction with quantum chemical calculations of gas phase reaction free energy to predict alkanolamines pka values. <br>

scholarly journals Preparation and the Microwave and Infrared Spectra of Vinyl Ketene

1979 ◽  
Vol 34 (11) ◽  
pp. 1269-1274 ◽  
Author(s):  
Erik Bjarnov
Keyword(s):  
Dipole Moment ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Normal Modes ◽  
Spectroscopic Constants ◽  
Electrical Dipole ◽  
Electrical Dipole Moment ◽  
Vacuum Pyrolysis ◽  
Modes Of Vibration

Vinyl ketene (1,3-butadiene-1-one) has been synthesized by vacuum pyrolysis of 3-butenoic 2-butenoic anhydride. The microwave and infrared spectra of vinyl ketene in the gas phase at room temperature have been studied. The trans-rotamer has been identified, and the spectroscopic constants were found to be Ã= 39571(48) MHz, B̃ = 2392.9252(28) MHz, C̃ = 2256.0089(28) MHz, ⊿j = 0.414(31) kHz, and ⊿JK = - 34.694(92) kHz. The electrical dipole moment was found to be 0.987(23) D with μa = 0.865(14) D and μb = 0.475(41) D. A tentative assignment has been made for 17 of the 21 normal modes of vibration

scholarly journals Exploration of Free Energy Surface and Thermal Effects on Relative Population and Infrared Spectrum of the Be6B11− Fluxional Cluster

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Carlos Emiliano Buelna-Garcia ◽  
José Luis Cabellos ◽  
Jesus Manuel Quiroz-Castillo ◽  
Gerardo Martinez-Guajardo ◽  
Cesar Castillo-Quevedo ◽  
...  
Keyword(s):  
Free Energy ◽  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Thermal Effects ◽  
Global Minimum ◽  
Energy Surface ◽  
Weighted Sums ◽  
Free Energy Surface ◽  
Temperature Dependent ◽  
Relative Population

The starting point to understanding cluster properties is the putative global minimum and all the nearby local energy minima; however, locating them is computationally expensive and difficult. The relative populations and spectroscopic properties that are a function of temperature can be approximately computed by employing statistical thermodynamics. Here, we investigate entropy-driven isomers distribution on Be6B11− clusters and the effect of temperature on their infrared spectroscopy and relative populations. We identify the vibration modes possessed by the cluster that significantly contribute to the zero-point energy. A couple of steps are considered for computing the temperature-dependent relative population: First, using a genetic algorithm coupled to density functional theory, we performed an extensive and systematic exploration of the potential/free energy surface of Be6B11− clusters to locate the putative global minimum and elucidate the low-energy structures. Second, the relative populations’ temperature effects are determined by considering the thermodynamic properties and Boltzmann factors. The temperature-dependent relative populations show that the entropies and temperature are essential for determining the global minimum. We compute the temperature-dependent total infrared spectra employing the Boltzmann factor weighted sums of each isomer’s infrared spectrum and find that at finite temperature, the total infrared spectrum is composed of an admixture of infrared spectra that corresponds to the spectra of the lowest-energy structure and its isomers located at higher energies. The methodology and results describe the thermal effects in the relative population and the infrared spectra.

scholarly journals IR photofragmentation of the phenyl cation: spectroscopy and fragmentation pathways

2021 ◽  
Vol 23 (7) ◽  
pp. 4334-4343
Author(s):  
Sandra D. Wiersma ◽  
Alessandra Candian ◽  
Joost M. Bakker ◽  
Giel Berden ◽  
John R. Eyler ◽  
...  
Keyword(s):  
Gas Phase ◽  
Spectral Range ◽  
Infrared Spectra ◽  
Fragmentation Pathways ◽  
Phenyl Cation

We present the gas-phase infrared spectra of the phenyl cation, phenylium, in its perprotio (C6H5+) and perdeutero (C6D5+) forms, in the 260–1925 cm−1 (5.2–38 μm) spectral range, and investigate the observed photofragmentation.

Gas phase infrared spectra and corresponding DFT calculations of , -diphenylpolyenes

2010 ◽  
Vol 259 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Lars Biemann ◽  
Michaela Braun ◽  
Karl Kleinermanns
Keyword(s):  
Dft Calculations ◽  
Gas Phase ◽  
Infrared Spectra

THE INFRARED SPECTRA AND STRUCTURE OF POLYALDEHYDES: IV. THE HIGHER POLYALDEHYDES

1959 ◽  
Vol 37 (10) ◽  
pp. 1718-1721 ◽  
Author(s):  
A. Novak ◽  
E. Whalley
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra

The polymers of n- and iso-butyraldehyde and n-valeraldehyde, which were made by subjecting the aldehydes to pressures of about 8 kb, have been examined by infrared spectroscopy. They are homologues of polyformaldehyde, having the formula HO(CHR•O)nH.

Linear free energy relationships in CN bond dissociations in molecular ions of 4-substitutedN-(2-furylmethyl)anilines in the gas phase

2007 ◽  
Vol 42 (11) ◽  
pp. 1496-1503 ◽  
Author(s):  
Eduardo A. Solano Espinoza ◽  
Elena Stashenko ◽  
Jairo Martínez ◽  
Uriel Mora ◽  
Vladimir Kouznetsov
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Molecular Ions ◽  
Linear Free Energy Relationships ◽  
Linear Free Energy ◽  
Energy Relationships
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