Self-assembly properties of polyphenylsulphonic acids and their alkali metal salts in aqueous solutions

Potassium and sodium 5'-phenyl-1,1':3',1 "-terphenyl-4-sulphonates (KPhTS and SPhTS) and the 2'-methyl derivatives (KMePhTS and SMePhTS) have been synthesized from the appropriate pyrylium salt. The procedure failed in the case of the corresponding lithium salts (LPhTS and LMePhTS). These were prepared by neutralization of the sulphonic acids. Solubilities of the alkali metal polyphenylsulphonates in water at 25 degrees C decrease in the order Li>Na>K. Conductivity data for these salts and the acids in water indicate formation of dimers in the low concentration range preceding the operational micellization concentration. Dilute solutions of lithium polyphenylsulphonates in aqueous LiCl form anisotropic, highly viscous systems which show marked time-dependent hypochromism. Results of dynamic light scattering measurements support the view that elongated stacks of the triphenylbenzene moieties are formed in such solutions. (C) 1998 Elsevier Science B.V.