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.2019 Sep 6;25(50):11772-11784.
doi: 10.1002/chem.201902625. Epub 2019 Aug 23.

Octacarbonyl Ion Complexes of Actinides [An(CO)8 ]+/- (An=Th, U) and the Role of f Orbitals in Metal-Ligand Bonding

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Octacarbonyl Ion Complexes of Actinides [An(CO)8 ]+/- (An=Th, U) and the Role of f Orbitals in Metal-Ligand Bonding

Chaoxian Chi et al. Chemistry..

Abstract

The octacarbonyl cation and anion complexes of actinide metals [An(CO)8 ]+/- (An=Th, U) are prepared in the gas phase and are studied by mass-selected infrared photodissociation spectroscopy. Both the octacarbonyl cations and anions have been characterized to be saturated coordinated complexes. Quantum chemical calculations by using density functional theory show that the [Th(CO)8 ]+ and [Th(CO)8 ]- complexes have a distorted octahedral (D4h ) equilibrium geometry and a doublet electronic ground state. Both the [U(CO)8 ]+ cation and the [U(CO)8 ]- anion exhibit cubic structures (Oh ) with a6 A1g ground state for the cation and a4 A1g ground state for the anion. The neutral species [Th(CO)8 ] (Oh ;1 A1g ) and [U(CO)8 ] (D4h ;5 B1u ) have also been calculated. Analysis of their electronic structures with the help on an energy decomposition method reveals that, along with the dominating 6d valence orbitals, there are significant 5f orbital participation in both the [An]←CO σ donation and [An]→CO π back donation interactions in the cations and anions, for which the electronic reference state of An has both occupied and vacant 5f AOs. The trend of the valence orbital contribution to the metal-CO bonds has the order of 6d≫5f>7s≈7p, with the 5f orbitals of uranium being more important than the 5f orbitals of thorium.

Keywords: IR spectroscopy; actinides; bonding analysis; electronic structure; octacarbonyl complexes.

© 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Mass spectra of a) thorium carbonyl cation and b) anion complexes.
Figure 2
Figure 2
Mass spectra of uranium a) carbonyl cations and b) carbonyl anion complexes.
Figure 3
Figure 3
Infrared photodissociation spectra of a) [Th(CO)8]−, b) [U(CO)8]−, c) [Th(CO)8]+, and d) [U(CO)8]+.
Figure 4
Figure 4
Calculated equilibrium geometries of the octacarbonyl complexes [An(CO)8]q (q=+1, 0, −1; An=Th, U) at the B3LYP‐D3(BJ)/def2‐TZVPPD/ECP level. The bond lengths are given in Å.
Figure 5
Figure 5
Splitting of the 5f, 6d, 7s, and 7p valence orbitals of uranium in the cubic (Oh) field of eight CO ligands and interactions with the 5σ and 2π* valence MOs of (CO)8. The eg orbital is fully occupied (n=1) in the quartet (4A1g) state of the anion [U(CO)8]−. It is occupied with two unpaired electrons (n=0) in the sextet (6A1g) state of the cation [U(CO)8]+. The MOs of U(CO)8+/− show the ordering of the calculated highest‐lying occupied and lowest‐lying vacant orbitals.
Figure 6
Figure 6
Contour isosurfaces (0.03 a.u.) of the Kohn–Sham molecular orbitals of (4A1g) [U(CO)8]− at the B3LYP‐D3(BJ)/def2‐TZVPPD/ECP level showing U−CO bonding.
Figure 7
Figure 7
Plot of the deformation densities Δρ(1)−Δρ(6), which are associated with the individual components of the orbital interactions ΔEorb(1)−ΔEorb(6) in a) [U(CO)8]+ and b) [U(CO)8]− by using Uq and (CO)8 as the interacting fragments (see Table 3). Only one component of the degenerate orbitals is shown. The color code of the charge flow is red→blue. Energy values are given in kcal mol−1. The eigenvalues |ν| indicate the size of the charge migration. For [U(CO)8]+, the isosurface values are 0.001 for Δρ(1)−Δρ(4) and 0.0008 for Δρ(5) and Δρ(6). For [U(CO)8]−, the isosurface values are 0.002 for Δρ(1), 0.001 for Δρ(2)−Δρ(4), and 0.0008 for Δρ(5) and Δρ(6).
Figure 8
Figure 8
Splitting of the 5f, 6d, 7s, and 7p valence orbitals of thorium in theD4h field of eight CO ligands and interactions with the 5σ and 2π* valence MOs of (CO)8 in a) octacarbonyl cation [Th(CO)8]+ and b) octacarbonyl anion [Th(CO)8]−. The MOs of Th(CO)8+/− show the ordering of the calculated highest‐lying occupied and lowest‐lying vacant orbitals.
Figure 9
Figure 9
Plot of the deformation densities Δρ(1)−Δρ(8), which are associated with the individual components of the orbital interactions ΔEorb(1)−ΔEorb(8) in [Th(CO)8]+ by using Th+ and (CO)8 as the interacting fragments (Table 4). Only one component of the degenerate orbitals is shown. The color code of the charge flow is red→blue. Energy values are given in kcal mol−1. The eigenvalues |ν| indicate the size of the charge migration. The isosurface values are 0.002 for Δρ(1), 0.001 for Δρ(2)−Δρ(5), and 0.0008 for Δρ(6)−Δρ(8).
Figure 10
Figure 10
Plot of the deformation densities Δρ(1)−Δρ(9′), which are associated with the individual components of the orbital interactions ΔEorb(1)−ΔEorb(9′) in [Th(CO)8]− by using Th and (CO)8− as the interacting fragments. The deformation density Δρ(9) comes from the interactions between Th− and (CO)8 (Table 4). Only one component of the degenerate orbitals is shown. The color code of the charge flow is red→blue. Energy values are given in kcal mol−1. The eigenvalues |ν| indicate the size of the charge migration. The isosurface values are 0.003 for Δρ(1) and Δρ(2) and 0.001 for others.
Figure 11
Figure 11
Principal components of the Dewar–Chatt–Duncanson model for transition‐metal carbonyl complexes in terms of TM←CO σ donation and TM→CO π backdonation.
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References

    1. Mendelejev L., Z. Chem. 1869, 12, 405–406.
    1. Langmuir I., Science 1921, 54, 59–67. - PubMed
    1. None
    1. Pyykkö P., J. Chem. Res. S 1979, 11, 380–381;
    1. Kutzelnigg W., Angew. Chem. Int. Ed. Engl. 1984, 23, 272–295;
    2. Angew. Chem. 1984, 96, 262–286;

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