The synthesis of polyhydroxy aryl sulphones and their tanning action on collagen in the presence of aluminium salts

Abstract

The action of a variety of polyphenolic compounds on collagen, when used in the presence of aluminium salts, has been investigated. This and further data obtained from deuterium exchange experiments on treated gelatine provide information on the mode of action of these tanning systems. A variety of diaryl sulphones has been prepared by a) standard methods, b) the action of arylsulphinic acids on o-quinones, and c) the action of arylsulphinic acids on arylthalliums. H and C n.m.r. spectroscopy, and infrared spectroscopy were employed in the structural analysis of prepared compounds. The proton-ligand stability constants of a number of polyphenolic compounds have been evaluated. The aluminium complexes of these polyphenolic compounds have been investigated by potentiometric and preparative methods. All constants were obtained after rigorous treatment of the experimental data by a) standard methods and b)computer techniques. Investigations by 15N n.m.r. and infrared spectroscopy indicate that glycine and [beta]-alanine may act as bidentate ligands towards aluminium.