Conformational ab initio study of ascorbic acid

Mora, M. A.; Meléndez, Francisco J.

doi:10.1016/s0166-1280(98)00288-7

Cited by 22 publications

(13 citation statements)

References 21 publications

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“…To sum up, our observed bands for AH 2 and AH − compare quite well with other spectral modeling results (4,15,23,26,46,(52)(53)(54)(55)(56)(57)(58)(59) and with the available experimental bands in the literature (39)(40)(41)(42)(43)(44)(45). We note, however, that the AH 2 sample of Panicker et al (45), presumably solid, seems to have been not entirely pure, because the Raman spectrum Table 7 Measured Raman spectral bands (in cm ) and assignments for aqueous solutions of ascorbic acid and sodium ascorbates, compared to literature values (39,44,46,48).…”

Section: Sodium Ascorbatesupporting

confidence: 88%

Investigation ofL(+)-Ascorbic acid with Raman spectroscopy in visible and UV light

Berg

2014

Applied Spectroscopy Reviews

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Section: Sodium Ascorbatesupporting

confidence: 88%

Investigation ofL(+)-Ascorbic acid with Raman spectroscopy in visible and UV light

Berg

2014

Applied Spectroscopy Reviews

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“…Al‐Laham et al 19 performed confirmational analysis of ascorbic acid by forcing the geometry of the ring to be constant and optimizing only the conformers of the side chain at the SCF level using the STO‐3G basis set. Mora and Melendez 20 optimized 36 conformers of ascorbic acid at the HF/6‐31G( p,d ), HF/6‐311+G( d,p ), and MP2/6‐31G ( d,p ) levels. The fully optimized gas phase structure was found to be closer to the so‐called crystallographic B structure.…”

Section: Introductionmentioning

confidence: 99%

Ab initio study of the structural properties of ascorbic acid (vitamin C)

Allen

Shukla

Reed

et al. 2006

Int J of Quantum Chemistry

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ABSTRACT:Geometries of the neutral and ionic tautomeric species of ascorbic acid were optimized at the density functional theory (DFT) level using the B3LYP functional. The radical species were evaluated using the unrestricted B3LYP method. Single-point energy calculations were also performed using the Møller-Plesset (MP2) and unrestricted MP2 (UMP2) methods for the closed-shell and open-shell systems, respectively. The effects of aqueous solution were evaluated using the conducting polarized continuum model (CPCM) and polarized continuum model (PCM). The geometries of most stable radicals in the respective groups were also optimized in the water solution using the CPCM model at the UB3LYP level. All calculation were performed using the 6-311ϩϩG(d,p) basis set. The nature of stationary points on the gas phase potential energy surfaces (PESs) was evaluated using vibrational frequency calculations; all geometries characterize local minima. The species obtained by the deprotonation of the O 3 site is the most stable monoanion of ascorbic acid. For the radical species, the structure obtained by the dehydrogenation of the O 3 site is the most stable monoradical. Among the radical anions, the species obtained by the deprotonation of the O 3 site and subsequent dehydrogenation of the O 2 site is the most stable in the gas phase and in an aqueous medium. The computed isotropic hyperfine coupling constants of this species were found to be in good agreement with the experimental data. Our investigation also supports the earlier findings that the oxidized species of ascorbic acid in water solution by the OH• radical is radical anion of the AAO 3• O 2 Ϫ form. The spin densities and molecular electrostatic potentials are also discussed.

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“…Otto et al calculated the influence of the side chain to the charge distribution of the ring, concluding that the side chain does not significantly influence the charge distribution . In the late 90s the first geometry optimizations at the HF and second‐order Møller–Plesset pertubation theory (MP2) level were performed . An energy surface was generated by rotations about two dihedral angles, that is, O12‐C11‐C9‐C4 and C2‐C4‐C9‐C11.…”

Section: Introductionmentioning

confidence: 99%

“…The obtained bond lengths and bond angles for the 10 energetically lowest conformers agreed quite well with X‐ray crystallographic data. Again the geometry optimizations of 36 conformers have shown that the atomic charges, as well as the geometry of the ring structure are almost independent of the chosen side chain . In 2004, Bannerjee et al investigated the influence of an approaching methylglyoxal on ascorbic acid at the DFT level of theory .…”

Section: Introductionmentioning

confidence: 99%

“…[9,[18][19][20][21][22][23][24][25] Since the side chain of ascorbic acid has several conformers, many local minima have been determined. [9,20,24,26,27] The first calculations involving AscH 2 and AscH 2 were carried out at Hartree-Fock (HF) level with a minimal STO-3G basis in the late 70s. [18,19] Carlson et al rotated two different dihedral angles of the side chain and concluded that the energetically lowest structure is in good agreement with the X-ray crystal structure.…”

Section: Introductionmentioning

confidence: 99%

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Quantum chemical study of the autoxidation of ascorbate

et al. 2016

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Reactions involved in the autoxidation of ascorbate have been investigated with quantum chemical first-principles and ab initio methods. Reaction energies and Gibbs energies of the reactions were calculated at the density functional theory level applying the gradient-corrected BP86 and the hybrid B3LYP functionals together with def2-TZVP basis sets. Results of single-point CC2, CCSD, and CCSD(T) calculations were used for calibration of the density functional theory data and show excellent agreement with the B3LYP values. Based on the Gibbs energy ascorbic acid AscH2 is found to be the energetically lowest species in aqueous solution, whereas the monoanion ascorbate AscH - is the most abundant one near pH = 7. Asc 2- was found to be the preferred reducing agent for autoxidation and oxidation processes. The results also support a metal-catalyzed synthesis of the reactive oxygen species H2 O2 according to a redox cycling mechanism proposed in literature. © 2016 Wiley Periodicals, Inc.

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Conformational ab initio study of ascorbic acid

Cited by 22 publications

References 21 publications

Investigation ofL(+)-Ascorbic acid with Raman spectroscopy in visible and UV light

Investigation ofL(+)-Ascorbic acid with Raman spectroscopy in visible and UV light

Ab initio study of the structural properties of ascorbic acid (vitamin C)

Quantum chemical study of the autoxidation of ascorbate

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