Solvent and substituent effects on the conformational equilibria and intramolecular hydrogen bonding of 4-substituted-2-hydroxybenzaldehydes

Blanco, Susana; Ferretti, F.H.

doi:10.1016/j.tetlet.2007.02.012

Cited by 7 publications

(2 citation statements)

References 15 publications

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“…The results of calculations of adducts with explicit water molecules support this suggestion, showing a broad hydrophobic region around the IHB (implying that the solvent molecules do not approach the IHB), whose extent is likely related to the distribution of H-bond donor/acceptor sites in acylphloroglucinols molecules. Although the hypothesis cannot be extended to other classes of compounds without specific investigation, it might be viable for classes of compounds for which analogous phenomena are observed (e.g., both the decrease, in solution, of the energy gap between the conformers with and without the IHB 64 and the lack of any correlation, in solution, between IHB lengths and the IHB enthalpies evaluated as differences between the enthalpies of the conformers with and without the IHB, have been reported 56 for 2-substituted phenols capable of forming IHB). It is also…”

Section: Discussionmentioning

confidence: 99%

A Computational Study of the Effects of Different Solvents on the Characteristics of the Intramolecular Hydrogen Bond in Acylphloroglucinols

Mammino

Kabanda

2009

J. Phys. Chem. A

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Acylphloroglucinols are a broad class of compounds, derivatives from 1,3,5-trihydroxybenzene, and exhibiting a variety of biological activities. They are characterized by the presence of at least one COR group, whose sp(2) O can form an intramolecular hydrogen bond with a neighboring phenolic OH. This H-bond plays dominant roles in determining conformational preferences and energy, and is expected to play significant roles in biological activity mechanisms, which strongly motivates the study of its characteristics in solution. A computational study of a representative number of actual and model structures with different R was carried out in three solvents with different polarities and different types of interactions with solute molecules: water, acetonitrile, and chloroform, utilizing the PCM model. Calculations were mostly performed at the HF/6-31G(d,p) level because of affordability reasons in view of the size and number of the structures considered (the smallest structures were also calculated at MP2/6-31+G(d,p) level). Comparison with the results of a previous study in vacuo shows similar patterns within each medium, pointing to similarities in the influence of relevant geometry factors on the characteristics of the H-bond. The medium appears to have little influence on the parameters of the H-bond. Comparison across media of the energy increase on H-bond removal (an indication of the H-bond strength) is complicated by the greater solvent stabilization of the conformer resulting from H-bond removal, with respect to the one in which the H-bond is present. Several factors, however, would point to a strength not too different from that observed in vacuo.

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Section: Discussionmentioning

confidence: 99%

A Computational Study of the Effects of Different Solvents on the Characteristics of the Intramolecular Hydrogen Bond in Acylphloroglucinols

Mammino

Kabanda

2009

J. Phys. Chem. A

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“…The electron affinities and antioxidant properties of different substituted chalcones have been successfully reproduced by Hicks et al [36] and Kozlowski et al [37], respectively. On the other hand, Blanco et al [38] studied the solvent and substituent effects on the conformational equilibria and the strength of the intramolecular hydrogen bond of 4-substituted-2-hydroxybenzaldehydes by means of B3LYP/6-31G(d). These works did not address the spectral properties that we investigated here.…”

Section: Introductionmentioning

confidence: 99%

An ab initio simulation of the UV/Visible spectra of substituted chalcones

et al. 2010

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a An ab initio simulation of the UV/Visible spectra of substituted chalcones Abstract:The electronic absorption spectra of 29 phenyl-ring substituted chalcones have been investigated with the time-dependent density functional theory (TD-DFT) and polarizable continuum TD-DFT (PCM-TD-DFT). It turns out that the hybrid PBE1PBE functional with the 6-31G basis set provide reliable λ max when the solvent effects are included in the model. Comparisons with experimental values lead to a mean absolute error of 12 nm (0.136 eV). Moreover, the observed substituent effects are reproduced by calculation qualitatively. The λ max of substituted chalcone in phenyl ring A is less sensitive to substitution than that in ring B. The linear correlation of Hammett's substituent constants (σ P ) with LUMO energies is better with respect to HOMO energies. The calculation reveals that the maximum absorption band mainly results from the π→π* transition from HOMO to LUMO. The analysis of the electron density plots of frontier molecular orbitals show that most transitions should be of valence excitation nature.

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Electronic structures and spectra of quinoline chalcones: DFT and TDDFT-PCM investigation

Xue

Liu

et al. 2011

Computational and Theoretical Chemistry

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Solvent and substituent effects on the conformational equilibria and intramolecular hydrogen bonding of 4-substituted-2-hydroxybenzaldehydes

Cited by 7 publications

References 15 publications

A Computational Study of the Effects of Different Solvents on the Characteristics of the Intramolecular Hydrogen Bond in Acylphloroglucinols

A Computational Study of the Effects of Different Solvents on the Characteristics of the Intramolecular Hydrogen Bond in Acylphloroglucinols

An ab initio simulation of the UV/Visible spectra of substituted chalcones

Electronic structures and spectra of quinoline chalcones: DFT and TDDFT-PCM investigation

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