σ-Alane complexes of chromium, tungsten, and manganese.

Photolytic ligand displacement and salt metathesis routes have been exploited to give access to κ(1) σ-alane complexes featuring Al-H bonds bound to [W(CO)(5)] and [Cp'Mn(CO)(2)] fragments, together with a related κ(2) complex of [Cr(CO)(4)]. Spectroscopic, crystallographic, and quantum chemical studies are consistent with the alane ligands acting predominantly as σ-donors, with the resulting binding energies calculated to be marginally greater than those found for related dihydrogen complexes.