Gold(I)middotmiddotmiddotLanthanide(III) Bonds in Discrete Heterobimetallic Compounds: A Combined Computational and Topological Study

The chemical nature of the ligand-unsupported gold(I)-lanthanide(III) bond in the proposed [LnIII(eta 5-Cp)2] [AuIPh2] (Ln-Au; LnIII = LaIII, EuIII, or LuIII; Cp = cyclopentadienide; Ph = phenyl) models is examined from a theoretical viewpoint. The covalent bond-like Au-Ln distances (Au-La, 2.95 angstrom; Au-Eu, 2.85 angstrom; Au-Lu, 2.78 angstrom) result from a strong interaction between the oppositely charged fragments (Delta EintMP2 > 600 kJ mol-1), including the aforementioned metal-metal bond and additional LnIII-Cipso and C-H center dot center dot center dot pi interactions. The Au-Ln bond has been characterized as a chemical bond rather than a strong metallophilic interaction with the aid of energy decomposition analysis, interaction region indicator, and quantum theory of atoms in molecules topological tools. The chemical nature of the Au-Ln bond cannot be fully ascribed to a covalent or an ionic model; an intermediate situation or a charge shift bond is proposed. The [AuIPh2]- anion has also been identified as a suitable lanthanide(III) emission sensitizer for La-Au and Lu-Au.

Automated summary

The chemical nature of the ligand-unsupported gold(I)-lanthanide(III) bond in the proposed [LnIII(eta 5-Cp)2] [AuIPh2] models was examined theoretically. The Au-Ln bond was characterized as a chemical bond rather than a strong metallophilic interaction. It was found that the nature of the Au-Ln bond cannot be fully explained by a covalent or an ionic model, suggesting an intermediate state or a charge shift bond. Additionally, the [AuIPh2]- anion was identified as a suitable lanthanide(III) emission sensitizer for La-Au and Lu-Au.