Aluminium-27 nuclear magnetic resonance studies of the hydrolysis of aluminium(III). Part 5. Slow hydrolysis using aluminium metal

Abstract

Aluminium-27 n.m.r. spectra are presented of solutions prepared by the relatively slow hydrolysis of AlCl₃ solutions with aluminium metal in the presence of mercury. The ways in which the spectra change with temperature or concentration are described and changes are also noted to occur as a function of magnetic field strength. It is not possible to give an unequivocal answer as to what is the nature of the species present in these solutions but there seem to be a variety of ions present which are quite easily interconvertible, contain octahedrally co-ordinated Al, and are associated in some way with fragments which resemble [AlO₄Al₁₂(OH)₂₄(H₂O)₁₂]⁷⁺(Al₁₃) since some tetrahedrally co-ordinated Al always seems to be present. Thus it is suggested that structures may consist of partial Al₁₃ units with octahedral units disposed as flexible chains and/or forming cross links.