Al-27 NMR studies of the hydrolysis of aluminium(III) chloride in non-aqueous media

Solutions prepared by equibrating solid AlCl3 and benzene have been studied by Al-27 NMR spectroscopy. Evidence of hydrolysis of AlCl3 is found, both under nominally anhydrous conditions and in the presence of added H2O. Resu lts are also reported for systems containing added gaseous HCl. The deconvo luted spectra show signals from rapidly exchanging ionic species, identifie d as H[AlCl4] and H[AlCl3(OH)], and a non-ionic species, formulated as [Cl2 Al(OH)](2), and based on an Al2O2 core, is also postulated. This species is structurally related to compounds reported by others in preparative work c arried out in nominally anhydrous AlCl3 and benzene. The solution probably also contains Al2Cl6, identified as a very broad resonance whose chemical s hift is estimated at approximately 98 ppm, relative to [Al(H2O)(6)](3+) = 0 . (C) 2000 Elsevier Science S.A. All rights reserved.