Étude des solutions de sels de trialcoylammonium par spectrométrie infrarouge, interaction entre cations trialcoylammonium et espèces nucléophiles

Moreno-Gonzalez, Edgar; Marraud, Michel; Néel, Jean

doi:10.1051/jcp/1977740563

Cited by 10 publications

(2 citation statements)

References 19 publications

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“…The Piv group was substituted for Boc in 1 ‘, and the Z group was eliminated by catalytic hydrogenolysis to yield the neutral reduced dipeptide 1 , which was then protonated quantitatively to 1 + by PF 6 - ·Et 2 O + H (Aldrich 17,638-9). The PF 6 - anion was selected to obtain an ammonium salt soluble in nonpolar media and for its weak interaction with ammonium anions, thus allowing the ammonium group to participate in intramolecular interactions . The methyleneoxypeptide 2 was prepared from the commercially available Boc-prolinol 10 (Merck 818348), which was treated by NaH and reacted with N -isopropyl-bromoacetamide ( 9 ) (Figure ) …”

Section: Methodsmentioning

confidence: 99%

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

et al. 1998

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The homologous RCO-Pro-Xaa-NHR‘ model pseudodipeptides containing the reduced peptide (CαCH2NHCα), reduced azapeptide (CαCH2NHNα), methyleneoxy (CαCH2OCα), and iminoazapeptide (CαCHNNα) surrogate of the middle amide group have been prepared. Their structural analysis has been carried out in solution by 1H NMR and IR spectroscopy and in the solid state by X-ray diffraction. The last three fragments, not protonated in the pH range 2−12, and the reduced fragment in its neutral amine form induce quite similar molecular structures characterized by a hydrogen bond between NHR‘ and the N/O atom replacing the amide NH group and closing a five-membered cycle. The neutral amine or protonated ammonium state of the reduced amide fragment, with a pK a value of about 7, depends on the environment. Protonation induces a conformational transition due to the strong proton donating properties of the ammonium group which interacts with the RCO carbonyl.

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Section: Methodsmentioning

confidence: 99%

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

et al. 1998

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“…Sandorfy et al (4,5) and Lord and McDowell (3,6,7) made this observation with Et3NHX, and Ebsworth and Sheppard (8) with Me,NDI, some 25 years ago. The studies that have been published since, both on triethylammonium (10,11,14,21,22), trimethylammonium (9,(23)(24)(25), and higher trialkylammonium (21) halides bear witness to the continued interest in this phenomenon, and are not confined to the simple halides but include other alkylammonium salts as well (12,13). The complex NH and ND stretching absorptions persist, with band sharpening and increased detail, down to liquid-helium temperature (3,6) and are observed also in solution spectra of these salts (9-11, 14, 21, 22).…”

Section: Comparison With Me3nhxmentioning

confidence: 99%

Triethylammonium halides, Et₃NHX (X = Cl, Br, I): simple structure, complex spectrum

James¹,

Cameron²,

Knop³

et al. 1985

Can. J. Chem.

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A crystal structure determination has shown that the ethyl groups in the three isostructural (P63mc, Z = 2) triethylammonium halides, Et3NHX (X = Cl, Br, I), at room temperature are orientationally disordered and the [Formula: see text] groups are linear by symmetry. The unusual extent and complexity of the NH and ND stretching absorptions in the ir spectra of all three compounds between 10 and 293 K are discussed in terms of Fermi resonance interactions. The centroid ν(NH) and ν(ND) frequencies extracted from the spectra correlate with the [Formula: see text] distances. It is shown that if Fermi resonance is the sole cause of the complexity of the stretching absorptions, then these centroids represent the ν(NH) and ν(ND) frequencies unperturbed by Fermi resonance. The centroid frequencies in the three halides are unusually low, pointing to strong [Formula: see text] hydrogen bonding.

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Étude Par Spectrométrie de Vibration, de L'Interaction Entre Les Halogénures de Trialkylammonium et Quelques Dérivés Phénoliques. II. Vibration v_NH⁺

Rulinda¹,

Zeegers‐Huyskens²

1978

Bulletin des Soc Chimique

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The vibrational spectrum of Et3N H+ C1-and Et3N H+ Br-has been examined in the vNH+ range. doublet while the infrared band profile is very large and shows a resonance window fixed at 2 5 1 0 cm-l. dissolved in 1,2 dichloroethane. The formation of hydrogen bonded complexes between the anions C1-or Br-and some phenol derivatives brings about a frequency shift of the vNH+ band toward higher wavenumbers. depends on the acidity of the phenol derivative and on its concentration. For these complexes, a window also appears at 2 5 1 0 cm-'; this negative absorption probably arises from a Fermi resonance with the rocking vibration of the methyl group.In the solid state, the Raman spectrum shows a well-defined non complexdes, nous a conduit P 6tudier celui-ci soit P l'dtat solide, soit en solution dans le dichlorodthane 1 , 2 (DCE)-329 -

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Étude des solutions de sels de trialcoylammonium par spectrométrie infrarouge, interaction entre cations trialcoylammonium et espèces nucléophiles

Cited by 10 publications

References 19 publications

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

Triethylammonium halides, Et₃NHX (X = Cl, Br, I): simple structure, complex spectrum

Étude Par Spectrométrie de Vibration, de L'Interaction Entre Les Halogénures de Trialkylammonium et Quelques Dérivés Phénoliques. II. Vibration v_NH⁺

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Étude des solutions de sels de trialcoylammonium par spectrométrie infrarouge, interaction entre cations trialcoylammonium et espèces nucléophiles

Cited by 10 publications

References 19 publications

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

Structural Comparison of Homologous Reduced Peptide, Reduced Azapeptide, Iminoazapeptide, and Methyleneoxypeptide Analogues

Triethylammonium halides, Et3NHX (X = Cl, Br, I): simple structure, complex spectrum

Étude Par Spectrométrie de Vibration, de L'Interaction Entre Les Halogénures de Trialkylammonium et Quelques Dérivés Phénoliques. II. Vibration vNH+

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Triethylammonium halides, Et₃NHX (X = Cl, Br, I): simple structure, complex spectrum

Étude Par Spectrométrie de Vibration, de L'Interaction Entre Les Halogénures de Trialkylammonium et Quelques Dérivés Phénoliques. II. Vibration v_NH⁺