A unique thorium‐thorium bond was observed in the crystalline tri‐thorium cluster [{Th(η8‐C8H8)(μ3‐Cl)2}3{K(THF)2}2]∞, though the claim of σ‐aromaticity for Th3bond has been questioned. Herein, a new type of core–shell syngenetic bonding model is proposed to describe the stability of this tri‐thorium cluster. The model involves a 3c–2e bond in the Th3core and a multicentered (ThCl2)3charge‐shift bond with 12 electrons scattering along the outer shell. To differentiate the strengths of the 3c–2e bond and the charge‐shift bond, the block‐localized wavefunction (BLW) method which falls into the ab initio valence bond (VB) theory is employed to construct a strictly core/shell localized state and its contributing covalent resonance structure for the Th3core bond. By comparing with the σ‐aromatic H3+and nonaromatic Li3+, the computed resonance energies and extra cyclic resonance energies confirm that this Th3core bond is truly delocalized and σ‐aromatic.
A unique thorium‐thorium bond was observed in the crystalline tri‐thorium cluster [{Th(η8‐C8H8)(μ3‐Cl)2}3{K(THF)2}2]∞, though the claim of σ‐aromaticity for Th3bond has been questioned. Herein, a new type of core–shell syngenetic bonding model is proposed to describe the stability of this tri‐thorium cluster. The model involves a 3c–2e bond in the Th3core and a multicentered (ThCl2)3charge‐shift bond with 12 electrons scattering along the outer shell. To differentiate the strengths of the 3c–2e bond and the charge‐shift bond, the block‐localized wavefunction (BLW) method which falls into the ab initio valence bond (VB) theory is employed to construct a strictly core/shell localized state and its contributing covalent resonance structure for the Th3core bond. By comparing with the σ‐aromatic H3+and nonaromatic Li3+, the computed resonance energies and extra cyclic resonance energies confirm that this Th3core bond is truly delocalized and σ‐aromatic.
more » « less- PAR ID:
- 10370812
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 134
- Issue:
- 37
- ISSN:
- 0044-8249
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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