Theoretical studies on tautomerism of imidazole-2-selenone

Chermhini, Alireza Najafi; Farrokhpour, Hossein; Teimouri, Abbas; Pourmoghaddas, Fatemah

doi:10.1007/s11224-012-0153-5

Cited by 12 publications

(3 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can accept a proton from a donor site of a molecule and give another proton to an acceptor site of the same molecule. Studies on the water‐assisted proton transfer reactions show that presence of a water molecule significantly decreases the activation energies of these reactions . Table reports E a , υ , and Δ G # of the isomerization and the keto–enol tautomerism of pyruvic acid catalyzed by the water molecule at 298 K. As seen, the activation energies decrease when a water molecule catalyzes the interconversion of the pyruvic acid isomers and tautomers.…”

Section: Resultsmentioning

confidence: 96%

Theoretical study on keto–enol tautomerism and isomerization in pyruvic acid

Valadbeigi

Farrokhpour

2013

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

Isomerization and tautomerism of 12 isomers of pyruvic acid including 4 keto and 8 enol forms were studied at the MP2 and B3LYP levels of theory using 6‐311++G(2df,p) basis set, separately. Activation energy (Ea), imaginary frequency (υ), and Gibbs free energy (ΔG#) of the considered isomerization and tautomerism reactions were calculated. Interconversion of the enol forms proceeds through two paths: (i) proton transfer and (ii) internal rotation. Activation energies for the proton transfer paths were in the range of 125–145 kJ/mol and for the internal rotation paths were in the range of 5–45 kJ/mol. Keto–enol tautomerism of pyruvic acid proceeds only through proton transfer route and their activation energies were in the range of 200–300 kJ/mol. Effect of microhydration on the transition state structures and activation energies was also investigated. It was found that the presence of a water molecule catalyzes the isomerization and tautomerism reactions of pyruvic acid so that the activation energies decrease. © 2013 Wiley Periodicals, Inc.

show abstract

Section: Resultsmentioning

confidence: 96%

Theoretical study on keto–enol tautomerism and isomerization in pyruvic acid

Valadbeigi

Farrokhpour

2013

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Tables 1 and 2 and contrasted with those got from the gas phase. These comparisons divulge that except isomer GG in the DFT/3BYP and G in the MP 2 , quantities of enthalpy and Gibbs free energy activation of the rest were reduced from gas phase to solvents [17,18].…”

Section: Resultsmentioning

confidence: 99%

Theoretical studies of ethylnitrolic acid using Gaussian

Nikafshar

Mirazizi

2017

J. Fundam and Appl Sci.

View full text Add to dashboard Cite

The tautomerism of all possible forms of ethylnitrolic acid was investigated theoretically in various environment including gas phase, ethanol, dimethyl sulfoxide (DMSO) and water.The calculations were carried out at DFT/B3LYP and MP 2 of theory singly. It was found that, form of B eythynitrolic acid is the most stable isomer in the both gas phase and solvent. The activation energies for conversion of A to R and B to A in the gas phase and solvent using two methods DFT/B3LY and MP 2 were obtained. Geometrical parameters of three isomers, A, B and R, were calculated by (DFT/B3LYP and MP 2 ) in the gas phase and solvent. Vibrational analysis and acidity constants (PK a ) of two isomers (A and R) were computed in the gas phase and water using DFT/B3LYP and MP 2 . After that, these quantities were evaluated with experimental values and it was determined that DFT/B3LYP is more accurate to obtain PK a .

show abstract

“…Chermhini et al [135] investigated the proton transfer reaction and tautomerism of imidazole-2-selenone compounds in the gas phase and in solution. MP2 and CAM-B3LYP (the exchange functional is a mixture of exact exchange, i.e., HF and DFT exchange; however, unlike B3LYP, the ratio of exact to DFT exchange varies in different regions of the molecule) methods were used.…”

Section: Issuementioning

confidence: 99%

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 3–4) and the discipline

et al. 2014

View full text Add to dashboard Cite

The contents of issues 3 and 4 for the calendar year 2013 are summarized in the current review of the journal Structural Chemistry. A brief thermochemical commentary is added to the summary of each paper. Abbreviations AIM Atoms in molecules BNNT Boron nitride nanotube CNC Carbon nanocone CSD Crystal structure determination DFT Density functional theory DNB 1,5-Dinitrobiuret EDA Energy decomposition analysis HF Hartree-Fock GED Gas electron diffraction GIAO Gauge-independent atomic orbital HOMA Harmonic oscillator measure of aromaticity MD Molecular dynamics MP Møller-Plesset perturbation MP2Second-order Møller-Plesset perturbation NRT Natural resonance theory ONIOM Our own N-layered integrated molecular orbital and molecular mechanics QTAIM Quantum theory of atoms-in-molecules NAO Natural atomic orbital NBO Natural bond orbital PES Potential energy surface

show abstract

Theoretical studies on tautomerism of imidazole-2-selenone

Cited by 12 publications

References 43 publications

Theoretical study on keto–enol tautomerism and isomerization in pyruvic acid

Theoretical study on keto–enol tautomerism and isomerization in pyruvic acid

Theoretical studies of ethylnitrolic acid using Gaussian

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 3–4) and the discipline

Contact Info

Product

Resources

About