A methodological analysis for the assessment of non-covalent π interactions

Quiñonero, David; Estarellas, Carolina; Frontera, Antonio; Deyà, Pere M.

doi:10.1016/j.cplett.2011.04.004

Cited by 24 publications

(13 citation statements)

References 44 publications

(49 reference statements)

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“…21 In some weak interactions dominated by dispersion effects like p-p stacking the MP2 method tends to overestimate the interaction energy, however it has been demonstrated that the dispersion term in ion-p interactions is small compared to electrostatic and induction terms, which dominate the interaction. 10 In addition, we have recently demonstrated 22 that the RI-MP2 method provides interaction energies for ion-p complexes, in good agreement with benchmark CCSD(T) results. For the C + -p complex 3, a stationary point is not found and it converges to complex 5.…”

Section: Theoretical Methodsmentioning

confidence: 64%

Radical cation (C˙+–π) and radical anion (A˙−–π) interactions with aromatic rings: energetic, orbitalic and spin density considerations

Estarellas

Frontera

Quiñonero

et al. 2011

Phys. Chem. Chem. Phys.

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Cation and anion-π interactions are important binding forces where aromatic rings are involved. In this manuscript we define and compare two related interactions that have not been reported so far, namely radical cation and radical anion-π interactions (C˙(+)-π and A˙(-)-π, respectively). Moreover, we compare the energetic features of these complexes with the related closed-shell interactions. Interestingly the C˙(+)-π interaction is more favourable than the standard cation-π interaction and the contrary is observed for the A˙(-)-π interaction. Changes in the aromatic character of the ring upon complexation of the ion have been studied using the nucleus-independent chemical shift (NICS) criterion. Orbitalic and spin density calculations of the complexes have been computed in order to investigate if spin transfer effects between the radical ions and the aromatic ring exist. We have analyzed the physical nature of the interactions by means of Bader's theory of "atoms-in-molecules" and partitioning the total interaction energy into individual components using the Molecular Interaction Potential with a polarization partition scheme. Finally, we describe an interesting biological example, which involves the tetrahydrobiopterin cofactor, where the presence of a radical ion-π interaction is important.

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Section: Theoretical Methodsmentioning

confidence: 64%

Radical cation (C˙+–π) and radical anion (A˙−–π) interactions with aromatic rings: energetic, orbitalic and spin density considerations

Estarellas

Frontera

Quiñonero

et al. 2011

Phys. Chem. Chem. Phys.

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“…The RI-MP2 method [57,58] applied to the study of cation-p and anion-p interactions is considerably faster than the MP2, and the interaction energies and equilibrium distances are almost identical for both methods [59,60]. We and others have recently demonstrated that this level of theory gives comparable results to the CCSD(T)/AVTZ//RI-MP2/aug-ccpVQZ level for several anion-p complexes [61,62]. The binding energy (E) was calculated at the same level with correction for the basis set superposition error (BSSE) using the counterpoise method [63].…”

Section: Theoretical Methodsmentioning

confidence: 75%

Tuning of the anion–π interaction

2012

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In this manuscript, we report an ab initio theoretical study (RI-MP2/aug-cc-pVDZ) that deals with the effect of having different electron acceptor molecules interacting with the aromatic moiety (s-triazine) on the anion-p interaction strength. Depending on the type and number of interacting molecules, a wide range of complexation energies can be obtained, and therefore, a tuning of the interaction strength can be adjusted. In addition, cooperativity effects between the anion-p and a variety of other noncovalent and convalent interactions are analyzed and compared. We have used Bader's theory of ''atoms-inmolecules'' to demonstrate that the electron density computed at the bond critical point that emerges upon complexation can be used not only as a measure of bond order but also as a measure of cooperativity and interplay between the noncovalent interactions that coexist in the same complex.

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“…30 We have recently demonstrated that this level of theory gives comparable results to the CCSD(T)/AVTZ//RI-MP2/aug-cc-pVQZ level for anion-p complexes of pyrazine. 31 To analyze the inter-molecular interactions, the atoms-in-molecules (AIM) theory was employed. 32 AIM is based upon those critical points where the gradient of the density, +r, vanishes.…”

Section: Theoretical Methodsmentioning

confidence: 99%