| Title
| - Energy Decomposition Analysis of Metal−Metal Bonding in [M2X8]2-(X = Cl, Br) Complexes of 5f (U, Np, Pu), 5d (W, Re, Os), and 4d (Mo,Tc, Ru) Elements
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| Abstract
| - The electronic structures of a series of [M2X8]2- (X = Cl, Br) complexes involving 5f (U, Np, Pu), 5d (W, Re, Os), and 4d (Mo, Tc, Ru) elements have been calculated using density functional theory, and a detailed analysis of the metal−metal interactions has been carried out using an energy decomposition approach.
- The electronic structures of a series of [M2X8]2- (X = Cl, Br) complexes involving 5f (U, Np, Pu), 5d (W, Re, Os),and 4d (Mo, Tc, Ru) elements have been calculated using density functional theory, and an energy decompositionapproach has been used to carry out a detailed analysis of the metal−metal interactions. The energy decompositionanalysis involves contributions from orbital interactions (mixing of occupied and unoccupied orbitals), electrostaticeffects (Coulombic attraction and repulsion), and Pauli repulsion (associated with four-electron two-orbital interactions).As previously observed for Mo, W, and U M2X6 species, the general results suggest that the overall metal−metalinteraction is considerably weaker or unfavorable in the actinide systems relative to the d-block analogues, as aconsequence of a significantly more destabilizing contribution from the combined Pauli and electrostatic (prerelaxation)effects. Although the orbital-mixing (postrelaxation) contribution to the total bonding energy is predicted to be largerin the actinide complexes, this is not sufficiently strong to compensate for the comparatively greater destabilizationoriginating from the Pauli-plus-electrostatic effects. A generally weak electrostatic contribution accounts for thelarge prerelaxation destabilization in the f-block systems, and ultimately for the weak or unfavorable nature ofmetal−metal bonding between the actinide elements. There is a greater variation in the energy decompositionresults across the [M2Cl8]2- series for the actinide than for the d-block elements, both in the general behavior andin some particular properties.
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