σ-Alane Complexes of Chromium, Tungsten, and Manganese

Photolytic ligand displacement and salt metathesis routes have been exploited to give access to κ1 σ-alane complexes featuring Al–H bonds bound to [W­(CO)5] and [Cp′Mn­(CO)2] fragments, together with a related κ2 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.