Agostic deformations based on electron delocalization in the alkyllithium-complex [{2-(Me3Si)2CLiC5H4N}2

Topological analysis of experimental and theoretical charge densities in the title complex [{2-(Me 3 Si) 2 CLiC 5 H 4 N} 2 ] 1 reveals the nature of the agostic deformation postulated for this complex: delocalization of the Li—C bonding electrons over the entire agostic alkyl group controls the formation of an acute Li—C—Si angle and thus a sufficient electronic saturation of the electron deficient lithium atom via secondary interactions. © 2001 Royal Society of Chemistry.