Structural and vibrational study on zwitterions of l-threonine in aqueous phase using the FT-Raman and SCRF calculations

Guzzetti, Karina Andrea; Brizuela, Alicia Beatriz; Romano, Élida; Brandán, Silvia Antonia

doi:10.1016/j.molstruc.2013.04.016

Cited by 25 publications

(13 citation statements)

References 42 publications

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“…In aqueous solution, the populations of α-monomeric forms increase significantly from 0.20 to 1.28 while the populations of the corresponding dimeric ones decrease from 0.15 to 0.00. Note that, in both monomeric and dimeric forms the higher dipole moment values are related to the most stable structures, a result also observed in other molecules [64][65][66]. When the energy values of two units of the β-forms in gas phase (-1297.8854 x 2= 2595.7708 Hartrees) are compared with those corresponding to the dimeric species (-2519.3660…”

Section: Structural Analysissupporting

confidence: 58%

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

Brandán¹,

Desk²

2017

SDRP-JCCMM

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In this work, monomeric and dimeric species of α-and β-cellulose were vibrationally characterized by using theoretical calculations derived from the density functional theory (DFT) and the scaled quantum mechanical force field (SQMFF) methodology. Here, the experimental available FT-IR and Raman spectra and the experimental available structure for the β-form were used in order to perform the assignments of the 129 normal vibration modes for both α-and β-cellulose forms. Raman bands and shoulders at 1258, 1153, 1123, 918, 907, 897, 864, 744, 727, 721, 483 and 281 cm -1 could probably support the presence of two proposed dimeric species of cellulose in the solid state. The structural properties reveal differences between both monomeric α-and β-cellulose species mainly evidenced by their molecular electrostatic potentials. The high dipole moment values and the higher populations for the β-form could support the major proportion found experimentally for this form. The volume contraction observed for the β-dimer could be related to their lower dipole moment in solution in relation to that observed in the gas phase. The reduction of the glycosidic angles for both forms in solution support their rigid structures, as was experimentally observed. The atomic charges on the O atoms belonging to the glucopyranose rings and to the glycosidic bonds (O33) present the lower values. The NBO and AIM studies suggest the presence of α-and β-cellulose in the two media but the major quantity of H bonds predicted for the β-form and their high donor-acceptor interaction values could support their most important proportion existent of this form in the earth. Similar reactivities were found in gas phase but the α-form is more reactive in solution than the other one probably because the electrophilicity and nucleophilicity for the β-form show lower values than the α ones.

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Section: Structural Analysissupporting

confidence: 58%

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

Brandán¹,

Desk²

2017

SDRP-JCCMM

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“…Table show the uncorrected solvation energy (Δ G u ), calculated as relative energy (Δ E ), and defined as the difference between the total energies in aqueous solutions and the values in gas phase. The Δ G ne values in aqueous solution were obtained using the PCM/SMD model, as reported for other compound in aqueous medium . Note that the Δ G c values for the C2 conformer increase significantly in aqueous solution in accordance with a higher volume variation, as seen in Supporting Information, Table S4.…”

Section: Resultsmentioning

confidence: 85%

“…The results for both media using the 6–31G* basis sets show for C1 and C2 in the two phases two BCPs while for C3 in both media are observed three BCPs. These BCPs have the typical properties of the closed‐shell interaction, which implies values of ρ (r) relatively low, the relationship |λ 1 |/λ 3 <1 and ▿ 2 ρ(r) positive indicating thus that the interaction is dominated by the charge contraction away from the interatomic surface toward each nucleus . A very important result for the three conformers is that the values of the properties decrease in aqueous solution as consequence of the hydration.…”

Section: Resultsmentioning

confidence: 99%

“…The experimental and calculated wavenumbers for all the normal vibration modes by using 6–31G* basis set together to the corresponding assignments for C1, C2, and C3 in both media are shown in Table . The vibrational assignments of the experimental bands to the normal thymidine vibration modes are based on the comparison with the previous partial assignments, with related molecules and with the results of the calculations performed here (Supporting Information, Tables S13, S14, and S15). It is important to note that in general in all spectra, there is good agreement between the experimental and theoretical spectra, especially in the higher wavenumbers regions.…”

Section: Resultsmentioning

confidence: 99%

“…) can be assigned to the two OH stretchings modes of deoxyribose ring, as was experimentally observed by Ivanov et al As predicted by calculations, the band at 3428 cm −1 is assigned to the N6H7 stretchings of all conformers of thymidine. Taking into account the assignments for compounds containing OH groups, the IR bands at 1288, 1197, and 1173 cm −1 are assigned to the OH in‐plane deformation modes for the three conformers while the corresponding out‐of‐plane deformation modes are associated with the Raman bands and shoulder, respectively, at 298, 276, and 180 cm −1 . These modes were not previously assigned by Ivanov et al…”

Section: Resultsmentioning

confidence: 99%

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A structural and vibrational investigation on the antiviral deoxyribonucleoside thymidine agent in gas and aqueous solution phases

Márquez

Brandán

2013

Int. J. Quantum Chem.

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A structural and vibrational study on the antiviral deoxyribonucleoside thymidine in gas and aqueous solution phases was performed combining the available infrared and Raman spectra with density functional theory (DFT) calculations. Three stable conformers for the title molecule were theoretically determined in both media by using the hybrid B3LYP method together with the 6–31G* basis set. The solvent effects were studied by means of the self‐consistent reaction field method employing the polarized continuum model. Complete assignments of the vibrational spectra of thymidine in both phases were performed combining the DFT calculations with Pulay's scaled quantum mechanics force field methodology. The bond orders, atomic charges, solvation energies, dipole moments, molecular electrostatic potentials, and force constants parameters were calculated for the three conformers of thymidine in gas phase and aqueous solution. Selected descriptors, such as chemical potential (µ), electronegativity (χ), global hardness (η), global softness (S), and global electrophilicity index (ω) were used to explain the exact nature of the interactions with electrophiles and/or nucleophiles and to predict the behavior of the three conformers of thymidine in gas and aqueous solution phases. © 2013 Wiley Periodicals, Inc.

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Promoting Homogeneous Zinc‐Ion Transfer Through Preferential Ion Coordination Effect in Gel Electrolyte for Stable Zinc Metal Batteries

Lee,

Han,

Jeon

et al. 2023

Advanced Science

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Aqueous zinc metal batteries (AZMBs) are emerging energy storage systems that are poised to replace conventional lithium‐ion batteries owing to their intrinsic safety, facile manufacturing process, economic benefits, and superior ionic conductivity. However, the issues of inferior anode reversibility and dendritic plating during operation remain challenging for the practical use of AZMBs. Herein, a gel electrolyte based on zwitterionic poly(sulfobetaine methacrylate) (poly(SBMA)) dissolved with different concentrations of ZnSO4 is proposed. Two‐dimensional correlation spectroscopy based on Raman analysis reveals an enhanced interaction priority between the polar groups in SBMA and the dissolved ions as electrolyte concentration increases, which establishes a robust interaction and renders homogeneous ion distribution. Attributable to the modified coordination, zwitterionic gel polymer electrolyte with 5 mol kg−1 of ZnSO4 (ZGPE‐5) facilitates stable zinc deposition and improves anode reversibility. By taking advantage of preferential coordination, a symmetrical cell evaluation employing ZGPE‐5 demonstrates a cycle life over 3600 h, where ZGPE‐5 also exerts a beneficial effect on the full cell cycling when assembled with Zn0.25V2O5 cathode. This study elucidates changes in the internal ion behavior that are dependent on electrolyte concentrations and pave the way for durable AZMBs.

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Structural and vibrational study on zwitterions of l-threonine in aqueous phase using the FT-Raman and SCRF calculations

Cited by 25 publications

References 42 publications

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

A structural and vibrational investigation on the antiviral deoxyribonucleoside thymidine agent in gas and aqueous solution phases

Promoting Homogeneous Zinc‐Ion Transfer Through Preferential Ion Coordination Effect in Gel Electrolyte for Stable Zinc Metal Batteries

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