Structural analysis of the amorphous sodium salt and aluminium hydroxide salt of sucrose sulphate

Abstract

The structure of the amorphous sodium salt and aluminium hydroxide salt of sucrose sulphate has been investigated using the radical distribution function together with the correlation method based on X-ray scattering intensity data. The most likely model for the short-range arrangements in the sodium salt and the aluminium hydroxide salt of sucrose sulphate is similar to that found in the crystal structure of potassium sucrose sulphate. Each sulphur atom is tetrahedrally surrounded by oxygen atoms at an average distance of 1.50 Å, while each sodium atom is octahedrally surrounded by oxygen atoms at a distance of 2.42 Å. The nearest-neighbouring Na—S distance is found to be r= 3.63 Å. Each aluminium atom is octahedrally surrounded by oxygen atoms at a distance r= 1.90 Å and two AlO₆ octahedra share an edge to form a dimer. The Al—Al distance of 2.88 Å is slightly longer than the octahedral edge (O—O) distance of 2.69 Å. Each dimer is probably surrounded by four SO₄ groups and the independent Al—S distances are 3.44 and 4.37 Å.