The 1H-6Li HOESY spectrum of [Li {Me2Si (H) Nt-Bu}] in toluene detects two major species with strong Si-H⊙⊙⊙ Li interactions, but no short Si-H⊙⊙⊙ Li contacts are present in its solvent-free X-ray structure. However, replacement of Li+ by Mg2+ results in agostic Si- H⊙⊙⊙ Mg contacts (2.2, 2.5 Å) in the X-ray crystal structure of [Mg2 {Me2Si (H) Nt-Bu} 4](shown).
