Theoretical study of intramolecular hydrogen bonding in the halo derivatives of 1-amino-3-imino-prop-1-ene

Emamian, Saeedreza; Tayyari, Sayyed Faramarz

doi:10.1007/s12039-013-0466-y

Cited by 22 publications

(12 citation statements)

References 40 publications

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“…The corresponding value for malonaldehyde is obtained at 0.0492 a.u. 45 As shown in 43 These results confirm some covalent nature in the IHB. The −G(rBCP)/V(rBCP) ratio, GVR, is also a descriptor for the nature of IHB.…”

Section: Aim Analysissupporting

confidence: 71%

“…(2) the GVR = 1 corresponds to a hydrogen bond energy of 7.87 ± 0.08 kcal/mol, which is in excellent agreement with the corresponding value reported for a bent N-H• • •N system, 8 kcal/mol. 45 A fairly good correlation (R 2 = 0.869) is also obtained between the hydroxyl proton chemical shift and E HB, as demonstrated in figure 3b.…”

Section: Also Showssupporting

confidence: 55%

“…To obtain a better correlation between Q and E HB , the data due to the 3-substituted derivatives are excluded from regression analysis (R 2 = 0.8814). Figure 5a indicates, as it has also been shown for the N-H• • • N system, 45 that the Gilli's symmetry coordinate, 48 Q, is not a good parameter for description of IHB strength, at least in systems with high degree of steric hindrance.…”

Section: Molecular Geometrymentioning

confidence: 68%

“…It has been shown that for those hydrogen bonds for which their strength is greater than 8 kcal/mol, GVRs are less than unity. 45 The calculated hydrogen bond energies, according to the Espinosa's equation, 47 along with the proton chemical shifts of bridge proton are listed in the last column of table 1. According to this table and considering the Rozas classification, 42 all IHBs investigated in this study are classified as medium strength.…”

Section: Also Showsmentioning

confidence: 99%

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Molecular structure and intramolecular hydrogen bonding in 2-hydroxybenzophenones: A theoretical study

et al. 2014

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The intramolecular hydrogen bonding (IHB) in a series of 3-, 4-and 5-substituted 2hydroxybenzophenone (HBP) is studied using density functional theory calculations. All calculations are performed at the B3LYP level, using 6-311++G** basis set. To understand the substitution effects on the nature of IHB and the electronic structure of the chelated ring system, the vibrational frequencies, 1 H chemical shift, topological parameters, natural bond orders and natural charges over atoms involved in the chelated ring of HBP and its derivatives were calculated. The Wiberg bond indices and the natural charges over atoms involved in the chelated ring have been computed using the natural bond orbital (NBO) analysis. The computations were further complemented with an atoms-in-molecules (AIM) topological analysis to characterize the nature of the IHB in the considered molecules. Several correlations between geometrical parameters, 1 H NMR chemical shift and topological parameters with the IHB strength are obtained.

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Section: Aim Analysissupporting

confidence: 71%

Section: Also Showssupporting

confidence: 55%

Section: Molecular Geometrymentioning

confidence: 68%

Section: Also Showsmentioning

confidence: 99%

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Molecular structure and intramolecular hydrogen bonding in 2-hydroxybenzophenones: A theoretical study

et al. 2014

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“…Afterwards, the results related to IHB strength have been compared with the experimental enolic proton chemical shifts, δOH which shows the effect of different substitutions in para-positions of phenyl ring on the IHB strength of the title molecules. The parameters related to IHB, such as EHB, ѵOH, γOH, δOH, geometrical and topological parameters would be correlated with the Hammett's para function, σp [25]. So, the electron donating/withdrawing substituent effects are discussed quantitatively by applying the Hammett equation.…”

Section: Calculation Levelmentioning

confidence: 99%

Application of Hammett equation to intramolecular hydrogen bond strength in para-substituted phenyl ring of trifluorobenzoylacetone and 1-aryl-1,3-diketone malonates

et al. 2018

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The stability of two stable cis-enol forms in two categories of β-diketones, including para-substituted of trifluorobenzoylacetone (X-TFBA) and 1-aryl-1,3-diketone malonates (X-ADM, X: H, NO2, OCH3, CH3, OH, CF3, F, Cl, and NH2) has been obtained by different theoretical methods. According to our results, the energy difference between the mentioned stable chelated enol forms for the titled compounds is negligible. The theoretical equilibrium constants between the two stable cis-enol of the mentioned molecules are in excellent agreement with the reported experimental equilibrium constant. In addition, the effect of different substitutions on the intramolecular hydrogen bond strength has been evaluated. The correlation between Hammett para-substituent constants, σp. with the theoretical and experimental parameters related to the strength of hydrogen bond in p-X-TFBA and p-X-ADM molecules also investigated by means of density functional theory calculations. The electronic effects of para-substitutions on the intramolecular hydrogen bond strength were determined by NMR and IR data related to intramolecular hydrogen bond strength, geometry, natural bond orbital results, and topological parameters. These parameters were correlated with the Hammett para-substituent constants, σp. Good linear correlations between σp and the several parameters related to the hydrogen bond strength, in this study were obtained.

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C―H···O hydrogen bonding interactions for sterically hindered phenols and their phenoxyl radicals

Wang

Liu

et al. 2018

J of Physical Organic Chem

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Sterically hindered phenols have been widely used as chain-breaking antioxidants in chemical and polymeric industries, and the remarkable stabilities of their phenoxyl radicals are generally attributed to the steric effects and resonance stabilization of the unpaired electron into the aromatic ring. Noncovalent interaction (NCI) analysis shows that there are four intramolecular C-H···O hydrogen bonds between oxygen atom and the ortho t-butyl C-H bonds for the sterically hindered phenoxyl radicals and their phenolic precursors. The C-H···O hydrogen bonds can be directly visualized and quantified from the reduced density gradient NCI isosurfaces and atoms-in-molecules analysis, respectively. Furthermore, the phenolic O-H bond strength decreases gradually with increasing volume of the ortho alkyl substituents in three different phenol model systems ( Table 5). The nice linear correlation of the O-H bond dissociation enthalpies with the Taft's steric parameters (Figure 8) provides additional evidences to support formation of the intramolecular C-H···O hydrogen bonds between oxygen atom and the ortho t-alkyl C-H bonds. KEYWORDS atoms-in-molecules (AIM), non-covalent interaction (NCI), sterically hindered phenols/phenoxyls, hydrogen bonding interactions

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Theoretical study of intramolecular hydrogen bonding in the halo derivatives of 1-amino-3-imino-prop-1-ene

Cited by 22 publications

References 40 publications

Molecular structure and intramolecular hydrogen bonding in 2-hydroxybenzophenones: A theoretical study

Molecular structure and intramolecular hydrogen bonding in 2-hydroxybenzophenones: A theoretical study

Application of Hammett equation to intramolecular hydrogen bond strength in para-substituted phenyl ring of trifluorobenzoylacetone and 1-aryl-1,3-diketone malonates

C―H···O hydrogen bonding interactions for sterically hindered phenols and their phenoxyl radicals

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