Fig. 3: Lithium–aluminium dimetallocene 2.
a, Synthesis of dimetallocene 2. b, The molecular structure of 2 in the crystal (side view and top view, displacement ellipsoids at 50% probability level, hydrogen atoms omitted for clarity, iPr groups drawn as ball-and-stick models). Selected experimental and theoretical [M06-2X/def2-SVP] bond lengths: Li1–Cpcent: 176.2(3)–176.6(1) [170.8] pm, Al1–Cpcent: 188.6(1)–189.3(1) [190.9] pm, Al1–Li1: 261.5(2) [265.8] pm. c, Laplacian distribution ∇2ρ(r) of 2 (M06-2X/de2-TZVPP//M06-2X/def2-SVP). Dashed red lines indicate areas of charge concentration (∇2ρ(r) < 0); solid blue lines indicate areas of charge depletion (∇2ρ(r) > 0) (bond ellipticity: 0.0). DI, delocalization index; Q, partial charge. d, Molecular orbital interaction diagram in eV for the Al–Li σ-bond in 2 (M06-2X/de2-TZVPP//M06-2X/def2-SVP; isodensity 0.05). e, DID plot (LMP2/cc-pVTZ). Orange/yellow/green zones indicate strong dispersion interactions, and blue/turquoise zones indicate weaker/diffuse contributions.
