Ferrocenylaluminum-pyridine adducts, lithium tetra(ferrocenyl)alanate, and the molecular structure of tri(ferrocenyl)aluminum-pyridine

Aluminum compounds with up to four ferrocenyl groups (Fc) linked to aluminum were prepared and characterized in solution by NMR spectroscopy (1H, 13C, 27Al NMR), and in one case, tri(ferrocenyl)aluminum-pyridine Fc3Al-py in the solid state by X-ray structural analysis. The attempts to stabilize the unsymmetrical species R2Al-Fc and RAl(Fc)2 (R = Me, Et) as the pyridine adducts were partially successful, although it proved difficult to suppress the formation of species containing Al–Cl functions completely.