Spectres vibrationnels d'éthers diéthyliques entre 300 et 80°K

Perchard, J. P.; Monier, J. C.; Dizabo, Pierre

doi:10.1016/0584-8539(71)80052-1

Cited by 31 publications

(7 citation statements)

References 12 publications

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“…Prior to our experimental work, the trans-gauche conformer had been studied by electron diffraction [4] and Raman spectroscopy in the gas phase, and by liquid-phase vibrational spectra [5,6]. All of those studies indicate that at room temperature the percentage of ether in this conformer is approximately 25-35%, and that it lies approximately 5-6 kJ mol À1 or 418-502 cm À1 above the ground state conformer, in agreement with ab initio determinations [4].…”

Section: Introductionmentioning

confidence: 61%

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The millimeter- and submillimeter-wave spectrum of the trans–gauche conformer of diethyl ether

Medvedev

Winnewisser

Lucia

et al. 2004

Journal of Molecular Spectroscopy

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Section: Introductionmentioning

confidence: 61%

“…Results from previous gas-phase electron diffraction work [4] and vibrational spectroscopy of diethyl ether [5,6] suggest that the room temperature population of the trans-gauche conformer is near 30%. Supporting ab initio calculations were carried out at the MP2/6-31G ** level of theory with PC-GAMESS [18,19].…”

Section: Rotational Spectrum and Analysismentioning

confidence: 93%

The millimeter- and submillimeter-wave spectrum of the trans–gauche conformer of diethyl ether

Medvedev

Winnewisser

Lucia

et al. 2004

Journal of Molecular Spectroscopy

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“…This value agrees well with the value of 1.37 ± 0.10 kcal/mol for the energy for the C-C-O-C gauche conformation in diethyl ether (DEE) as determined from the temperature dependence of the vibrational spectra of DEE. 33 This energy corresponds to the difference in energy between the tg and tt conformers of DEE. Agreement between the ab initio value for the C-C-O-C gauche energy and the experimental value is well within the estimated uncertainty of 0.2-0.3 kcal/mol in the ab initio values.…”

Section: Resultsmentioning

confidence: 99%

Conformation of 1,2-dimethoxyethane from ab initio electronic structure calculations

Jaffe¹,

Smith²,

Yoon³

1993

J. Phys. Chem.

141

192

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The conformational properties of 1 ,Zdimethoxyethane (DME) have been analyzed in detail using ab initio electronic structure calculations in order to better understand the influence of oxygen gauche effects on the conformation energies and populations of DME. Our calculations indicate that the energy of the gauche conformation of the 0-C-C-O bond relative to the trans conformation, which reflects the strength of the oxygen gauche effect in DME, depends strongly not only on the basis set size but also on electron correlation effects. Specifically, the energy of the tgt conformation of DME relative to the ttt conformation was determined for various basis sets at both the SCF and MP2 levels. MP2 level calculations with a D95+(2df,p) basis set, a Dunning double-tbasis set of the form (lOs6p2dlf/4slp)/[5s2p2dlf/2slp], yield an energy ofca. 0.1 kcal/mol for the gauche conformation, as compared with 0.75 kcal/mol for MP2 level calculations with the smaller D95** basis set and 1.0 kcal/mol for SCF level calculations employing the D95+(2df,p) basis set. A salient result of our investigation is the determination that the energy of the tgigF conformation lies only ca. 0.2 kcal/mol above that of the ttt conformation, apparently due to strong 0-H attractions. Finally, we find that the conformer populations of DME obtained from conformational energies determined at the MP2 level with a D95+(2df,p) basis set are in good agreement with those derived from electron diffraction experiments and can be used to successfully reproduce experimental values of N M R vicinal coupling constants and dipole moments for DME.

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“…DEE is one of the important dipolar aprotic solvents, used as a medium in various chemical reactions. Apart from this, the structural characterization of DEE and DES has gained a lot of attention in the research community. − The structural aspects of these molecules are interesting because of the presence of two flexible ethyl chains that give rise to multiple conformers of these molecules. In almost all the cases, the microwave spectroscopy has been employed to elucidate the structure of the conformers.…”

Section: Introductionmentioning

confidence: 99%

O−H···O versus O−H···S Hydrogen Bonding. 3. IR−UV Double Resonance Study of Hydrogen Bonded Complexes ofp-Cresol with Diethyl Ether and Its Sulfur Analog

Biswal

Wategaonkar

2010

J. Phys. Chem. A

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In this work the hydrogen bonded complexes of diethyl ether (DEE) and diethyl sulfide (DES) with p-cresol (p-CR) were investigated. Only one conformer of the p-CR.DEE complex and three conformers of the p-CR.DES complex were found to be present under the supersonic jet expansion conditions. The conformational assignments were done with the help of IR-UV double resonance studies and ab initio calculations. The red shifts in the OH stretching frequency for the O-H...O and O-H...S hydrogen bonded complexes were quite close to each other. In fact, one of the p-CR.DES conformers showed a slightly larger red shift in the OH stretch than that in the p-CR.DEE conformer, which suggests that in this case sulfur is not a weak hydrogen bond acceptor as noted previously in case of the p-CR.H(2)O and p-CR.H(2)S complexes (Biswal et al. J. Phys. Chem. A 2009, 113, 5633). The natural bond orbital analysis also shows that the extent of overlap between sulfur lone pair orbitals (LP) and OH antibonding orbital (sigma*(OH)) was comparable to the oxygen (LP) and sigma*(OH) overlap, consistent with the similar magnitudes of the red shifts of OH stretch in the DES and DEE complexes. The computed binding energy of the p-CR.DES complex, however, was about 80% of the p-CR.DEE complex. The electron densities at the bond critical points indicated that the O-H...S interaction was weaker than the O-H...O interaction in this particular system also. The important finding of this study was that the IR red shifts in the H-bond donor X-H stretching frequency were not quite consistent with the computed binding energies and the atoms-in-molecules analysis contrary to the general understanding. Energy decomposition analysis suggests that O-H...S hydrogen bonding interaction is dispersive in nature and the dispersion contribution decreases with the increase in the length of the alkyl chain of the "S" hydrogen bond acceptor.

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Spectres vibrationnels d'éthers diéthyliques entre 300 et 80°K

Cited by 31 publications

References 12 publications

The millimeter- and submillimeter-wave spectrum of the trans–gauche conformer of diethyl ether

The millimeter- and submillimeter-wave spectrum of the trans–gauche conformer of diethyl ether

Conformation of 1,2-dimethoxyethane from ab initio electronic structure calculations

O−H···O versus O−H···S Hydrogen Bonding. 3. IR−UV Double Resonance Study of Hydrogen Bonded Complexes ofp-Cresol with Diethyl Ether and Its Sulfur Analog

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