Ab initio quantum chemical and NMR study of the symmetric monooximes of 1,2,3-phenalenetrione and 1,2,3-indantrione

Enchev, Venelin; Ivanova, Galya; Ugrinov, Angel; Neykov, G.D.; Minchev, S.; Stoyanov, Neyko

doi:10.1016/s0022-2860(97)00268-8

Cited by 15 publications

(13 citation statements)

References 16 publications

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“…Thus, the chemical shift of this carbon shows a strong dependence on H-bonding, unlike for the above-mentioned carboxyl carbon. The position of the methyl group 13 C signal is supported by our calculations for the tetramer (9.7 ppm). Calculations of this chemical shift for the monomers are surprisingly overestimated by around 5-9 ppm.…”

Section: Theoretical Energies and Geometriessupporting

confidence: 75%

“…However, the energy values of the other forms differ only slightly form the most energetically favorable (0.3-4.9 kcal mol 1 ). 13 These are clearly attributable to the carboxyl, the oximic and the methyl carbons, respectively. The best fit for the carbon atom of the COOH group was obtained for the tetrameric structure (167.9 ppm).…”

Section: Theoretical Energies and Geometriesmentioning

confidence: 98%

“…1 H and 13 C NMR spectra at room temperature were measured on a Gemini 300 spectrometer operating at 300 MHz for protons and 75 MHz for carbon nuclei. The spectra were recorded for 0.20 and 0.11 M solutions in DMSOd 6 ( 1 H and 13 C) for 1 and 2, respectively (3 is insoluble in this solvent), and also in ¾0.07 M ( 1 H) and ¾0.18 M ( 13 C) solutions in D 2 O for 1 and 3 (2 is insoluble in D 2 O).…”

Section: 23 -25mentioning

confidence: 99%

“…The spectra were referenced to TMS or the solvent signal. The 1 H NMR spectra were obtained with a spectral width of 4786 Hz and an acquisition time of 3.5 s and the 13 C spectra with a spectral width of 17 354 Hz and an acquisition time of 0.944 s.…”

Section: 23 -25mentioning

confidence: 99%

“…Several NMR studies of oximes have been published 12 -22 but, to the best of our knowledge, there has been no study of oximes which contain both oximic and carboxyl groups. We present here 1 H and 13 C NMR spectra of the above-mentioned oximes that were measured in deuterated dimethyl sulfoxide (DMSOd 6 ) and deuterium oxide (D 2 O) at room temperature and in deuterated acetone (acetone-d 6 ) at low temperature and discuss possible structures that may be responsible for the observed resonances.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and theoretical NMR study of selected oxocarboxylic acid oximes

Malek¹,

Vala²,

Kozłowski³

et al. 2003

Magnetic Reson in Chemistry

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1H and 13C NMR spectra of the oxocarboxylic acid oximes 2-hydroxyiminopropanoic acid (1), 2-(4-methylthiazol-2-yl)-2-(hydroxyimino)acetic acid (2) and 2-cyano-2-(hydroxyimino)acetic acid (3) were measured in DMSO-d6, D2O and acetone-d6 solutions. The data indicate the presence of hydrogen bonding in 1 and 2 and a strong electron-withdrawing effect due to the cyano group in 3. The effect of intra- and intermolecular hydrogen bonding on the hydrogen and carbon chemical shifts in these molecules was studied theoretically. Total energy calculations of the stability of various hydrogen-bonded species, in addition to equilibrium parameters and chemical shifts, were calculated using ab initio methods (RHF, MP2) and density functional theory (B3LYP), implemented in the Gaussian 98 software package. The gauge-including atomic orbital (GIAO) method was used to predict magnetic shielding constants. Chemical shift calculations for the most stable species agree fairly well with the observed data, especially for the hydroxyl protons. Substituents adjacent to the alpha-carbon show some influence of the oximic and carboxyl groups on the 13C chemical shifts, as expected for groups with different polar and anisotropic character.

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Section: Theoretical Energies and Geometriessupporting

confidence: 75%

Section: Theoretical Energies and Geometriesmentioning

confidence: 98%

Section: 23 -25mentioning

confidence: 99%

Section: 23 -25mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental and theoretical NMR study of selected oxocarboxylic acid oximes

Malek¹,

Vala²,

Kozłowski³

et al. 2003

Magnetic Reson in Chemistry

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Computational Study on the Effects of Substituents and Functional Groups in the Isomerization of 1‐ and 2‐Substituted Propenes, Acetaldimines, and Aldehydes

Chuang

Lien

2004

Eur J Org Chem

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We have performed ab initio molecular orbital calculations on 1-and 2-substituted propenes, acetaldimines, and aldehydes -H 3 CC(X)=Y and XCH 2 CH=Y (Y = CH 2 , NH, O; X = H, CH 3 , NH 2 , OH, F) -to investigate the effects that substituents and functional groups have on their isoelectronic (except X = H) tautomerism. Structures for all stationary points (keto forms, enol forms, and transitions states) were optimized at the HF/6−31G**, MP2(full)/6−31G*, and B3LYP/6−31G** levels of theory and were characterized by frequency calculations. We performed intrinsic reaction coordinate (IRC) calculations at the HF/6−31G** level of theory to connect the transition structures with their local minima along the reaction path. In the transition structures, the migrating H4 atom is slightly out of plane, with a dihedral angle H4−C2−C1−Y3 (d4) of Ͻ 12°. In the keto−enol and imine−enamine series, the keto forms are thermodynamically more stable than their counterparts by ca. 30 kcal·mol −1 re-

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Conformational Analysis, Infrared, and Fluorescence Spectra of 1-Phenyl-1,2-propandione 1-oxime and Related Tautomers: Experimental and Theoretical Study

Bekhradnia

Arshadi

2007

Monatsh. Chem.

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Ab initio quantum chemical and NMR study of the symmetric monooximes of 1,2,3-phenalenetrione and 1,2,3-indantrione

Cited by 15 publications

References 16 publications

Experimental and theoretical NMR study of selected oxocarboxylic acid oximes

Experimental and theoretical NMR study of selected oxocarboxylic acid oximes

Computational Study on the Effects of Substituents and Functional Groups in the Isomerization of 1‐ and 2‐Substituted Propenes, Acetaldimines, and Aldehydes

Conformational Analysis, Infrared, and Fluorescence Spectra of 1-Phenyl-1,2-propandione 1-oxime and Related Tautomers: Experimental and Theoretical Study

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