Modeling Copper(I) Complexes:\, SIBFA Molecular Mechanics versus Ab Initio Energetics and Geometrical Arrangements

International audienceSIBFA parametrization is extended to the closed-shell Cu(I) cation. This parametrization introduces the cation polarization up to quadrupolar effects and the metal-ligand charge transfer. The results obtained are compared to the corresponding ab initio quantum-chemical quantities given by intermolecular interaction energy decomposition and MP2 runs. Mono- and polycoordinated complexes of Cu(I) with O-, S-, and N-containing ligands are considered. An extension to systems containing two and three Cu(I) cations, found in copper metalloenzyme active sites, such as cytochrome C oxidase and hemocyanin, and supramolecular systems, is reported. The results obtained show that in such cases SIBFA is able to give geometrical arrangements in reasonable agreement with experimental data and interaction energy values close to those given by ab initio computations. With respect to MP2 results, covering interaction energy range of ≈400 kcal/mol, the interaction energy rms amounts to 7.6 kcal/mol

Theoretical quantification of the electrostatic contribution to complexes involving organolithium compounds

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The electroaffinity of O2 by DFT and coupled MCSCF/perturbation approaches : a computational experiment

The electroaffinity of the O2 molecule is revisited using density functional theory (DFT) and perturbation treatments built on a MCSCF wavefunction that includes most of the non-dynamic correlation effects (MC/P approach). Using a standard 6–31 + G* basis set, DFT treatments based on BLYP or B3LYP functionals provide electroaffinities of the order of +0.6 eV that compare favorably to experiment. Coupled MCSCF/perturbation treatments using an Epstein-Nesbet partition of the molecular Hamiltonian give a more accurate value of +0.492 eV in excellent agreement with the most recent experimental data (+0.431 eV) as well as with highest-level purely variational ab initio treatments which are far less tractable for larger systems. The analysis of the results in terms of differential correlation effects made it possible to identify the failure of the previous MCSCF-limited treatments as arising from the dynamic correlation of the electron pair describing the σO---:O bond

Improved Formulas for the Calculation of the Electrostatic Contribution to the Intermolecular Interaction Energy from Multipolar Expansion of the Electronic Distribution

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Why Are Monomeric Lithium Amides Planar?

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Influence of the Correlation, Aggregation, and Solvation on ab initio Computed Li−C, Li−N, and Li−Li NMR Coupling Constants

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A DFT Theoretical Analysis of Aldehyde Condensation Pathways onto Methyllithium, Lithium Dimethylamide, and Their Aggregates

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