Theoretical study of the influence of para- and meta-substituents on X-pyridine⋯HF hydrogen bonding

Ebrahimi, Ali; Habibi, Mostafa; Masoodi, Hamid Reza

doi:10.1016/j.chemphys.2007.08.012

Cited by 20 publications

(13 citation statements)

References 25 publications

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“…5), such that the meta‐ or para‐positions cannot be considered alone. Therefore, we regarded σ total (σ total = σ p + σ m ) for complex C. −(Δ G −Δ G °)/2.3RT versus σ 37, 38 (for Δ G

_{1}^{d}

and Δ G

_{2}^{w}

) and σ total (for Δ G

_{1}^{w}

) characterize that the correlation coefficients are equal to 0.89 (except for X = p‐NH 2 and p‐N(CH 3 ) 2 ), 0.93 and 0.95 for Δ G

_{1}^{d}

, Δ G

_{1}^{w}

, and Δ G

_{2}^{w}

, respectively. Because of positive sign of ρ, complexation and effective activation energies increase by electron‐withdrawing substituents and decrease by electron‐donating groups.…”

Section: Resultsmentioning

confidence: 99%

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase

Ebrahimi

Habibi‐Khorassani

Doosti

2011

Int J of Quantum Chemistry

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Nucleophilic substitution reaction between some substituted benzyl chlorides and chloride ion has been investigated by ab initio and DFT methods. New calculated energy data are in better agreement with experimental data. The electronwithdrawing groups increase the energy barriers and the electron-donating groups decrease them. The changes of geometrical parameters and energy data are in good agreement with the results of atoms in molecules and natural bond orbital analyses. The relationship between Hammett coefficients and energy data (and geometry parameters) has been established and the q constant has been calculated for this reaction.

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_{1}^{d}

and Δ G

_{2}^{w}

) and σ total (for Δ G

_{1}^{w}

) characterize that the correlation coefficients are equal to 0.89 (except for X = p‐NH 2 and p‐N(CH 3 ) 2 ), 0.93 and 0.95 for Δ G

_{1}^{d}

, Δ G

_{1}^{w}

, and Δ G

_{2}^{w}

, respectively. Because of positive sign of ρ, complexation and effective activation energies increase by electron‐withdrawing substituents and decrease by electron‐donating groups.…”

Section: Resultsmentioning

confidence: 99%

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase

Ebrahimi

Habibi‐Khorassani

Doosti

2011

Int J of Quantum Chemistry

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“…However, relationships between couplings and the value of the bond critical point in fluorine-fluorine through-space interactions have been found. [20,25,26] Besides, Iranian authors described in two 27] and calculated B3LYP/6-311++G(d,p) 2h J NF values [28] for complexes of para 11 and meta substituted pyridines 12 with hydrogen fluoride, although they do not compare them nor their report 1 We have calculated 1 J FH and 1 J NH for the compounds of Table 7 plus three pyridine/HF complexes: 11a, R = H, 11b, R = O − and 11c, R = NH 3 + (Table 8). The data of Table 8 can be compared in several ways.…”

Section: Atoms In Molecules Analysismentioning

confidence: 96%

“…The data of Table 8 can be compared in several ways. For instance, in Figure 3 are reported the plots corresponding to the coupling constants and to the ρs: pyridines/HF [27,28] ; squares, 10 values of Figure 3 (right) is a similar representation but now concerning bond critical points. In both figures, compound 11b occupy a central position suggesting where similar compounds can be found.…”

Section: Atoms In Molecules Analysismentioning

confidence: 96%

A DFT and AIM analysis of the spin–spin couplings across the hydrogen bond in the 2‐fluorobenzamide and related compounds

Alkorta

Elguero

Limbach

et al. 2009

Magnetic Reson in Chemistry

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In 1975 a large number of coupling constants were measured in 2-fluorobenzamide labeled with (15)N. Some of them were assigned to couplings through intramolecular N-H...F hydrogen bonds (HBs). These couplings change dramatically when CDCl(3) is replaced by DMSO-d(6). In this theoretical paper we provide density functional theory (DFT) calculations that justify the existence of a weak HB in the absence of solvent, while solvents that act as HB acceptors break down the intramolecular hydrogen bond (IMHB) of 2-fluorobenzamide. Atoms in molecules (AIM) analyses and Steiner-Limbach plots were used to analyze the structure of the compounds.

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“…The maximum and minimum values correspond to the N(CH 3 ) 2 and NO 2 substituents, respectively, (with the exception of ρ N2H in the complex 1 where the minimum value corresponds to the CN substituent). The topological properties of ρ calculated at the BCP of the intermolecular hydrogen bonds may be treated as a measure of the hydrogen bond strength [42][43][44] Because of linear relationship between ΔE and ρ NH values, the ΔE = cρ NH can be used for the calculation of individual H-bond energies in the complex 1 (see Table 4). All individual H-bond energies calculated for the complex 1 are lower than the values calculated for the complexes 2 and 3.…”

Section: Aim and Nbo Analysismentioning

confidence: 99%

The NHF Interactions in the X-Pyridazine Complexes: Substituent Effects and Energy Components

Ebrahimi

Habibi‐Khorassani

Akher

et al. 2012

Advances in Physical Chemistry

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The effects of substituents on the N⋯HF interactions in the X-pyridazine (X = N(CH3)2, NHCH3, NH2, C2H5, CH3, OCH3, OH, CN, OF, NO2, F, Br, Cl, and ) complexes have been studied at the B3LYP/6-311++G(d,p) level of theory. In all complexes, the binding energies increase for the electron-donating substituents and decrease for the electron-withdrawing substituents. A negative cooperativity is observed for two hydrogen bond interactions. There are meaningful relationships between the Hammett constants and the energy data and the results of population analysis in the binary and ternary complexes. Symmetryadapted perturbation theory (SAPT) analysis was also carried out to unveil the nature of hydrogen bond in the complexes 2 and 3. The electron-donating substituents increase the magnitude of the SAPT interaction energy components and the electron-withdrawing substituents decrease those components. The highest/lowest change is observed for the component. The effect of C2H5 (or CH3) on different components is higher than OCH3 in the complex 2 while the trend is reversed in the complex 3. It is demonstrated that the electrostatic interaction plays a main role in the interaction, although induction and dispersion interactions are also important.

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Theoretical study of the influence of para- and meta-substituents on X-pyridine⋯HF hydrogen bonding

Cited by 20 publications

References 25 publications

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase

A DFT and AIM analysis of the spin–spin couplings across the hydrogen bond in the 2‐fluorobenzamide and related compounds

The NHF Interactions in the X-Pyridazine Complexes: Substituent Effects and Energy Components

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Theoretical study of the influence of para- and meta-substituents on X-pyridine⋯HF hydrogen bonding

Cited by 20 publications

References 25 publications

Substituent effects on SN2 reaction between substituted benzyl chloride and chloride ion in gas phase

Substituent effects on SN2 reaction between substituted benzyl chloride and chloride ion in gas phase

A DFT and AIM analysis of the spin–spin couplings across the hydrogen bond in the 2‐fluorobenzamide and related compounds

The NHF Interactions in the X-Pyridazine Complexes: Substituent Effects and Energy Components

Contact Info

Product

Resources

About

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase

Substituent effects on S_N2 reaction between substituted benzyl chloride and chloride ion in gas phase