The 1 : 1 and 2 : 3 interactions of aluminium isopropoxide with bifunctional tridentate Schiff bases, derived by the condensation of o-hydroxyacetophenone with hydroxyalkylamines [such as 2-hydroxyethylamine, 2-hydroxy-1-propylamine, 1-hydroxy-2-methyl-2-propylamine and 1-hydroxy-2-butylamine] have been investigated. The resulting derivatives of the types, Al(OPrt)(SB) and Al2(SB)3 (where SB2- is the anion of the corresponding Schiff base, SBH2) have been isolated in almost quantitative yields. The ebullioscopic determination of molecular weights in benzene has shown the isopropoxy derivatives to be dimers, whereas the dialuminium-tris-Schiff base derivatives to be monomers. The infrared spectra of these compounds have been recorded and plausible structures indicated.