ROLE OF SOLVATION AND DESOLVATION IN POLYMER CATALYSIS .3. THE INFLUENCE OF HIGH-PRESSURES ON THE ALKALINE FADING REACTIONS OF TRIPHENYLMETHANE DYES CATALYZED BY MACROIONS

Alkaline fading reactions of ethyl violet and crystal violet were studied in the presence of polyelectrolytes under high pressure, and the significant role of the hydrophobic hydration effect in polyelectrolyte ″catalysis″ was demonstrated in terms of the volume of activation. Polyelectrolytes used are poly-4-vinylpyridine quaternized with n-cetylbromide (5 mol-%) (Cl6BzPVP), 3-6 ionen polymer, (polybrene), sodium polyethylenesulfonate (NaPES), and sodium polystyrenesulfonate (NaPSS). These four samples, respectively, enhanced, slightly retarded, retarded and strongly impeded the reactions. The influence of a cationic surfactant, cetyltrimethylammonium bromide, on the rates and the activation parameters was similar to that of C16BzPVP. These experimental findings indicate that the hydrophobic macrocations such as C16BzPVP facilitated the formation of the ″ice-berg″ structure of water around the activated complex so that the complex and the macrocations are incorporated in the ice-berg structure.