Reactions of the dimeric aluminium alkyls, (AlR3)2 where R = Me or Et, and the alkylaluminium compounds, (R2AlX)2 where R = Me or Et, X = F, Cl, Br, I, CN, NMe2, NEt2, SMe, or OEt, and (RAIX2)2, where R = Et, X = Cl or I, with various ligand molecules, e.g. NMe3, C5H5N, PMe3, Et2O, and Me2SO, have been investigated. The properties of the adducts are described, and the relative acceptor properties of the different aluminium compounds are compared.