An Effective Continuum Model for the Liquid-to-Gas Phase Change in a Porous Medium Driven by Solute Diffusion: II. Constant Liquid Withdrawal Rates

The scheme of gas production from gas hydrates on underwater slopes is offered. The existing modern technologies which have to be used are listed. The mathematical apparatus for calculations describes a filtration of polyphase environments in the relative frame elastic porous medium with phase change.

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Solvent and temperature effects on the tautomerization of a carbonitrile molecule: A conductor-like polarizable continuum model (CPCM) study

Main Group Chemistry ◽

10.3233/mgc-210016 ◽

2021 ◽

Vol 20 (1) ◽

pp. 59-68

Author(s):

Zohreh Khanjari ◽

Bita Mohtat ◽

Reza Ghiasi ◽

Hoorieh Djahaniani ◽

Farahnaz Kargar Behbahani

Keyword(s):

Gas Phase ◽

Solvent Effects ◽

Continuum Model ◽

Solvent Polarity ◽

Polarizable Continuum Model ◽

Dielectric Constants ◽

Frontier Orbitals ◽

Reaction Field ◽

Polarizable Continuum ◽

Homo Lumo

This research examined the effects of solvent polarity and temperature on the tautomerization of a carbonitrile molecule at CAM-B3LYP/6-311G (d,p) level of theory. The selected solvents were n-hexane, diethyl ether, pyridine, ethanol, methanol, and water. The solvent effects were examined by the self-consistent reaction field theory (SCRF) based on conductor-like polarizable continuum model (CPCM). The solvent effects were explored on the energy barrier, frontier orbitals energies, and HOMO-LUMO gap. Dependencies of thermodynamic parameters (ΔG and ΔH) on the dielectric constants of solvents were also tested. Specifically, the temperature dependencies of the thermodynamics parameters were studied within 100–1000 K range. The rate constant of the tautomerism reaction was computed from 300 to 1200 K, in the gas phase.

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THEORETICAL CALCULATION OF pKb VALUES FOR ANILINES AND SULFONAMIDE DRUGS IN AQUEOUS SOLUTION

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633612500307 ◽

2012 ◽

Vol 11 (02) ◽

pp. 283-295 ◽

Cited By ~ 19

Author(s):

BAHRAM GHALAMI-CHOOBAR ◽

ALI GHIAMI-SHOMAMI ◽

PARIA NIKPARSA

Keyword(s):

Gas Phase ◽

Continuum Model ◽

Correlation Equation ◽

Polarizable Continuum Model ◽

Free Energies ◽

Pcm Model ◽

Solvation Models ◽

Polarizable Continuum ◽

Better Than ◽

Good Agreement

In this work, calculations of p K b values have been performed for aniline and its substituted derivatives and sulfonamide drugs by using Gaussian 98 software package. Gas-phase energies were calculated with HF /6-31 G ** and B3LYP /6-31 G ** levels of theory. Free energies of solvation have been computed using the polarizable continuum model (PCM), conductor-like polarizable continuum model (CPCM) and the integral equation formalism-polarizable continuum model (IEFPCM) at the same levels which have been used for geometry determination in the gas-phase. The results show that the calculated p K b values using the B3LYP /6-31 G ** are better than those using the corresponding HF /6-31 G **. At first, the correlation equation was found to determine the p K b values of the investigated anilines. Then, this correlation equation was used to calculate the p K b values of the sulfonamide drugs. The results obtained indicate that the PCM model is a suitable solvation model for calculating p K b values in comparison to the other solvation models. For the investigated compounds a good agreement between the experimental and the calculated p K b values was also observed.

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