Aluminium-27 nuclear magnetic resonance studies of the hydrolysis of aluminium(III). Part 4. Hydrolysis using sodium carbonate

Abstract

Hydrolysis with sodium carbonate carried out in the shortest possible time and without subsequent ageing produces solutions whose composition depends upon the degree of hydrolysis achieved and contain varying proportions of [Al(OH₂)₆]³⁺, [(H₂O)₄Al(OH)₂Al(OH₂)₄]⁴⁺, and [AlO₄Al₁₂(OH)₂₄(OH₂)₁₂]⁷⁺ and apparently no other species, although many new ions can form quite quickly as the solutions age. The fundamental hydrolysis reaction of Al³⁺ seems to involve only these three species and so can be described in surprisingly simple terms. As soon as any ageing is allowed then a variety of reactions can occur leading in general to the production of larger polymers, some of which may have definable structures.