The equilibrium OH bond length

Demaison, J.; Herman, Michel; Liévin, Jacques

doi:10.1080/01442350701371919

Cited by 55 publications

(27 citation statements)

References 158 publications

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“…Upon cis → trans isomerization, the QCISD calculated OH bond length changes (from 96.56 pm in I to 96.18 pm in VI), and as it is well-known, the corresponding νOH frequency should increase. 32 The C=O bond also shortens (from 120.70 pm in I to 120.08 pm in VI), and is in agreement with the observed increase of the νC=O frequency in form VI. 33 A similar effect was also previously reported to occur upon near-IR-induced generation of the trans O=C−O−H conformers of formic or acetic acids at the expense of the corresponding cis conformers.…”

Section: Narrowband Near-ir Generation Of a High-energy Conformer supporting

confidence: 82%

Near-IR laser generation of a high-energy conformer of L-alanine and the mechanism of its decay in a low-temperature nitrogen matrix

Nunes

Lapiński

Fausto

et al. 2013

The Journal of Chemical Physics

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Monomers of L-alanine (ALA) were isolated in cryogenic nitrogen matrices at 14 K. Two conformers were identified for the compound trapped from the gas-phase into the solid nitrogen environment. The potential energy surface (PES) of ALA was theoretically calculated at the MP2 and QCISD levels. Twelve minima were located on this PES. Seven low-energy conformers fall within the 0-10 kJ mol(-1) range and should be appreciably populated in the equilibrium gas phase prior to deposition. Observation of only two forms in the matrices is explained in terms of calculated barriers to conformational rearrangements. All conformers with the O=C-O-H moiety in the cis orientation are separated by low barriers and collapse to the most stable form I during deposition of the matrix onto the low-temperature substrate. The second observed form II has the O=C-O-H group in the trans orientation. The remaining trans forms have very high relative energies (between 24 and 30 kJ mol(-1)) and are not populated. The high-energy trans form VI, that differs from I only by rotation of the OH group, was found to be separated from other conformers by barriers that are high enough to open a perspective for its stabilization in a matrix. The form VI was photoproduced in situ by narrow-band near-infrared irradiation of the samples at 6935-6910 cm(-1), where the first overtone of the OH stretching vibration in form I appears. The photogenerated form VI decays in N2 matrices back to conformer I with a characteristic decay time of ∼15 min. The mechanism of the VI → I relaxation is rationalized in terms of the proton tunneling.

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Section: Narrowband Near-ir Generation Of a High-energy Conformer supporting

confidence: 82%

Near-IR laser generation of a high-energy conformer of L-alanine and the mechanism of its decay in a low-temperature nitrogen matrix

Nunes

Lapiński

Fausto

et al. 2013

The Journal of Chemical Physics

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“…These values suggest that this bond is breaking since it is longer that the OH bond in the reactants (0.98 Å). Such a short bond length at the equilibrium is in agreement with other experimental and computational data reported in the literature . Accordingly, the bond between the basic nitrogen and the same proton (N b –H, Table ) is in the range 1.28–1.40 Å, suggesting that the upcoming formation of the new bond is not complete, as the equilibrium distance is around 1.1 Å.…”

Section: Resultssupporting

confidence: 90%

Conformational Mobility and Efficiency in Supramolecular Catalysis. A Computational Approach to Evaluate the Performances of Enzyme Mimics

Salvio

D’Abramo

2020

Eur J Org Chem

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In the present study, we apply a computational approach, based on DFT calculations and molecular dynamics simulations, to investigate the catalytic behavior of four supramolecular catalysts active in the cleavage of phosphodiesters. The QM data indicate the operation of a synchronous associative mechanism with limited differences in the structures and energies of the transition states. The comparison with the experimental data, expressed in terms of effective molarity (EM), suggests that the difference in catalytic performance are not ascribable to a difference in the enthalpy of activation. On the

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“…For target values, experimental geometries are only available for methanol (t) 20,32−37 and ethanol (t), 8,24,38 whereas coupled cluster geometries are available for methanol (t), ethanol (t), propan-2-ol (g−), and propanol (Tt) (see Supporting Information Tables 1 and 2). 5,39 First, let us consider the performance of MP2/aV5Z.…”

Section: Discussionmentioning

confidence: 99%

Small Alcohols Revisited: CCSD(T) Relative Potential Energies for the Minima, First- and Second-Order Saddle Points, and Torsion-Coupled Surfaces

Heiden

Reith

2018

ACS Omega

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The elucidation of conformations and relative potential energies (rPEs) of small molecules has a long history across a diverse range of fields. Periodically, it is helpful to revisit what conformations have been investigated and to provide a consistent theoretical framework for which clear comparisons can be made. In this paper, we compute the minima, first- and second-order saddle points, and torsion-coupled surfaces for methanol, ethanol, propan-2-ol, and propanol using consistent high-level MP2 and CCSD(T) methods. While for certain molecules more rigorous methods were employed, the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pV5Z theory level was used throughout to provide relative energies of all minima and first-order saddle points. The rPE surfaces were uniformly computed at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ level. To the best of our knowledge, this represents the most extensive study for alcohols of this kind, revealing some new aspects. Especially for propanol, we report several new conformations that were previously not investigated. Moreover, two metrics are included in our analysis that quantify how the selected surfaces are similar to one another and hence improve our understanding of the relationship between these alcohols.

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The equilibrium OH bond length

Cited by 55 publications

References 158 publications

Near-IR laser generation of a high-energy conformer of L-alanine and the mechanism of its decay in a low-temperature nitrogen matrix

Near-IR laser generation of a high-energy conformer of L-alanine and the mechanism of its decay in a low-temperature nitrogen matrix

Conformational Mobility and Efficiency in Supramolecular Catalysis. A Computational Approach to Evaluate the Performances of Enzyme Mimics

Small Alcohols Revisited: CCSD(T) Relative Potential Energies for the Minima, First- and Second-Order Saddle Points, and Torsion-Coupled Surfaces

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