The characterization of stationary points in the potential energy surface of difluoromethane dimer

Ebrahimi, Ali; Roohi, Hossein; Habibi, S.M.

doi:10.1016/j.theochem.2004.07.021

Cited by 11 publications

(7 citation statements)

References 22 publications

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“…Considering the monomer as reference, it is seen that while the establishment of N-H⋅ ⋅ ⋅N interaction promotes the lengthening of the N-H covalent bond, the formation of C-H⋅ ⋅ ⋅N interactions leads to a shortening of the C-H covalent bond. This distinct behaviour of the N-H and C-H covalent bonds has already been observed, both experimentally and theoretically, for other hydrogen bonded molecular clusters [11,[27][28][29][30][31][32][33], and has been correlated with a balance between two main effects that act in opposite directions. One is the net electron density gain in the X-H bond region, that promotes a contraction of the covalent X-H bond, and the other is the attractive interaction between the positively charged hydrogen atom and the electron rich acceptor N-atom, which leads to lengthening of Figure 4: Comparison of the CP-uncorrected and CP-corrected CEHB values predicted by the B97D calculations for the O3d (which assembles the most stable geometry predicted for trimeric water clusters [25,26]), O3a, and O4a iPram clusters.…”

Section: Structural Analysissupporting

confidence: 68%

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

Amado

Fiuza

Carvalho

et al. 2013

Journal of Chemistry

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The effects of implicitly considering the effects of hydrogen bonding on the molecular properties, such as vibrational frequencies, were inferred on the basis of DFT calculations. Several clusters of isopropylamine were assembled and theoretically characterized. The results showed that maximum H-bond cooperativity is achieved when the amine group acts simultaneously as donor and acceptor. The effect of H-bond cooperativity manifests itself in the relative cluster stability and on the structural and vibrational frequency predictions. Referring to the vibrational frequencies it was found that theNH2stretching and torsion vibrational modes are the most affected by the amine involvement in hydrogen bonding. Both stretching modes were found to be significantly redshifted relative to the monomer. TheNH2torsional mode, on the other hand, was found to be blueshifted up to 350 cm-1. Finally, the comparative study between the theory levels performed allows to conclude that the small 6-31G* basis set is able to stabilize weakC–H⋯Ninteractions as long as the new dispersion corrected DFT methods are considered. The impairments observed with conventional DFT methods for describing weak interactions may be overcome with the improvement of basis set, but the associated increase of computational costs may turn the calculations unfeasible.

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Section: Structural Analysissupporting

confidence: 68%

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

Amado

Fiuza

Carvalho

et al. 2013

Journal of Chemistry

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“…The few rotationally resolved investigations of molecular adducts in which the monomers are held together by CH⋅⋅⋅F and CH⋅⋅⋅O WHBs have shown the specificity and directionality of these interactions 4–9. For example, the dimer of difluoromethane is stabilized only by CH⋅⋅⋅F bridges4 and several theoretical investigations have been reported on this type of interaction 10–12…”

Section: Spectroscopic Constants For Adduct Ch3f⋅chf3[a]mentioning

confidence: 99%

Weak CH⋅⋅⋅F Bridges and Internal Dynamics in the CH₃F⋅CHF₃ Molecular Complex

et al. 2005

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“…This is called an “improper H-bond”, and one of the main characteristic of them is the blue shift of the νX–H stretching frequencies [45,46,47,48]. The nature of the C–H⋯F–C bond in different fluoromethanes was studied by Kryachko et al [49] and Ebrahimi et al [50]; these studies demonstrated the improper H-bond character of the C–H proton donor induced by the presence of the fluorine atom. A systematic analysis of these “improper H-bonds”, for the molecular class of CH2X2, which would include also chlorine, bromine, and iodine atoms, could not be found in the literature.…”

Section: Introductionmentioning

confidence: 99%

Intermolecular Interaction in Methylene Halide (CH2F2, CH2Cl2, CH2Br2 and CH2I2) Dimers

Almásy

Bende

2019

Molecules

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The intermolecular interaction in difluoromethane, dichloromethane, dibromomethane, and diiodomethane dimers has been investigated using high level quantum chemical methods. The potential energy curve of intermolecular interaction along the C⋯C bond distance obtained using the coupled-cluster theory with singles, doubles, and perturbative triples excitations CCSD(T) were compared with values given by the same method, but applying the local (LCCSD(T)) and the explicitly correlated (CCSD(T)-F12) approximations. The accuracy of other theoretical methods—Hartree–Fock (HF), second order Møller–Plesset perturbation (MP2), and dispersion corrected DFT theory—were also presented. In the case of MP2 level, the canonical and the local-correlation cases combined with the density-fitting technique (DF-LMP2)theories were considered, while for the dispersion-corrected DFT, the empirically-corrected BLYP-D and the M06-2Xexchange-correlation functionals were applied. In all cases, the aug-cc-pVTZ basis set was used, and the results were corrected for the basis set superposition error (BSSE) using the counterpoise method. For each molecular system, several dimer geometries were found, and their mutual orientations were compared with the nearest neighbor orientations obtained in recent neutron scattering studies. The nature of the intermolecular interaction energy was discussed.

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The characterization of stationary points in the potential energy surface of difluoromethane dimer

Cited by 11 publications

References 22 publications

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

Weak CH⋅⋅⋅F Bridges and Internal Dynamics in the CH₃F⋅CHF₃ Molecular Complex

Intermolecular Interaction in Methylene Halide (CH2F2, CH2Cl2, CH2Br2 and CH2I2) Dimers

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The characterization of stationary points in the potential energy surface of difluoromethane dimer

Cited by 11 publications

References 22 publications

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

Weak CH⋅⋅⋅F Bridges and Internal Dynamics in the CH3F⋅CHF3 Molecular Complex

Intermolecular Interaction in Methylene Halide (CH2F2, CH2Cl2, CH2Br2 and CH2I2) Dimers

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Weak CH⋅⋅⋅F Bridges and Internal Dynamics in the CH₃F⋅CHF₃ Molecular Complex