scholarly journals Dimerization of Acetic Acid in the Gas Phase—NMR Experiments and Quantum-Chemical Calculations

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2150 ◽  
Author(s):  
Ondřej Socha ◽  
Martin Dračínský
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Low Temperatures ◽  
Variable Temperature ◽  
Glass Tube ◽  
Variable Pressure ◽  
Liquid Phases ◽  
Donor And Acceptor ◽  
Moller Plesset ◽  
Triple Excitation

Due to the nature of the carboxylic group, acetic acid can serve as both a donor and acceptor of a hydrogen bond. Gaseous acetic acid is known to form cyclic dimers with two strong hydrogen bonds. However, trimeric and various oligomeric structures have also been hypothesized to exist in both the gas and liquid phases of acetic acid. In this work, a combination of gas-phase NMR experiments and advanced computational approaches were employed in order to validate the basic dimerization model of gaseous acetic acid. The gas-phase experiments performed in a glass tube revealed interactions of acetic acid with the glass surface. On the other hand, variable-temperature and variable-pressure NMR parameters obtained for acetic acid in a polymer insert provided thermodynamic parameters that were in excellent agreement with the MP2 (the second order Møller–Plesset perturbation theory) and CCSD(T) (coupled cluster with single, double and perturbative triple excitation) calculations based on the basic dimerization model. A slight disparity between the theoretical dimerization model and the experimental data was revealed only at low temperatures. This observation might indicate the presence of other, entropically disfavored, supramolecular structures at low temperatures.

Investigation of Adsorption Effect of Carbon Monoxide on Coniine: A DFT Study

2021 ◽  
Vol 17 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Mehrnoosh Khaleghian ◽  
Marina Murashko ◽  
Mahin Ahmadianarog ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Adsorption Effect ◽  
Chemical Shift Tensors ◽  
Solvent Water ◽  
Donor And Acceptor ◽  
Before And After ◽  
Electron Donor And Acceptor

: For the first time in the present study, the non-bonded interaction of the Coniine (C8H17N) with carbon monoxide (CO) was investigated by density functional theory (DFT/M062X/6-311+G*) in the gas phase and solvent water. The adsorption of the CO over C8H17N was affected on the electronic properties such as EHOMO, ELUMO, the energy gap between LUMO and HOMO, global hardness. Furthermore, chemical shift tensors and natural charge of the C8H17N and complex C8H17N/CO were determined and discussed. According to the natural bond orbital (NBO) results, the molecule C8H17N and CO play as both electron donor and acceptor at the complex C8H17N/CO in the gas phase and solvent water. On the other hand, the charge transfer is occurred between the bonding, antibonding or nonbonding orbitals in two molecules C8H17N and CO. We have also investigated the charge distribution for the complex C8H17N/CO by molecular electrostatic potential (MEP) calculations using the M062X/6-311+G* level of theory. The electronic spectra of the C8H17N and complex C8H17N/CO were calculated by time dependent DFT (TD-DFT) for investigation of the maximum wavelength value of the C8H17N before and after the non-bonded interaction with the CO in the gas phase and solvent water. Therefore, C8H17N can be used as strong absorbers for air purification and reduce environmental pollution.

scholarly journals Abraham model correlations for estimating solute transfer of neutral molecules into anhydrous acetic acid from water and from the gas phase

2015 ◽  
Vol 212 ◽  
pp. 16-22 ◽  
Author(s):  
Dawn M. Stovall ◽  
Amber Schmidt ◽  
Colleen Dai ◽  
Shoshana Zhang ◽  
William E. Acree ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Solute Transfer ◽  
Abraham Model ◽  
Anhydrous Acetic Acid

Photofragmentation of gas-phase acetic acid and acetamide clusters in the vacuum ultraviolet region

2017 ◽  
Vol 147 (19) ◽  
pp. 194302 ◽  
Author(s):  
Marta Berholts ◽  
Hanna Myllynen ◽  
Kuno Kooser ◽  
Eero Itälä ◽  
Sari Granroth ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
Vacuum Ultraviolet ◽  
Ultraviolet Region ◽  
Vacuum Ultraviolet Region

Versatile Cryostated Optically Transparent Thin-Layer Electrochemical (OTTLE) Cell for Variable-Temperature UV-Vis/IR Spectroelectrochemical Studies

1994 ◽  
Vol 48 (12) ◽  
pp. 1522-1528 ◽  
Author(s):  
F. Hartl ◽  
H. Luyten ◽  
H. A. Nieuwenhuis ◽  
G. C. Schoemaker
Keyword(s):  
Thin Layer ◽  
Low Temperatures ◽  
Variable Temperature ◽  
Experimental Setup ◽  
Strictly Anaerobic ◽  
Carbonyl Complexes ◽  
Anaerobic Conditions ◽  
Optically Transparent ◽  
Solution Layer ◽  
Preset Temperature

This article describes the construction of a novel optically transparent thin-layer electrochemical (OTTLE) cell for IR and UV-Vis spectroelectrochemical experiments at variable temperature. The cell has a three-electrode set melt-sealed into a smooth polyethylene spacer which is sandwiched between two CaF2 windows. The width of this spacer (0.18–0.20 mm) defines the thickness of the thin solution layer. The whole electrode assembly is housed in a thermostated Cu block of the OTTLE cell which fits into a double-walled nitrogen-bath cryostat. The experimental setup permits relatively fast electrolysis within the tested temperature range of 295 to 173 K under strictly anaerobic conditions and protection of light-sensitive compounds. Other important merits of the cell design include lack of leakage, facile cleaning, almost negligible variation of the preset temperature, and facile manipulation in the course of the experiments. The applicability of the variable-temperature IR/UV-Vis OTTLE cell is demonstrated by stabilization of a few electrogenerated carbonyl complexes of Mn(I) and Ru(II) with 3,5-di- tert. butyl-1,2-benzo(semi)quinone (DB(S)Q) and N, N′-diisopropyl-1,4-diaza-1,3-butadiene (iPr-DAB) ligands, respectively, at appropriately low temperatures.

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