SOLVENT SUBSTRATE EFFECTS ON THE MICELLE-CATALYZED AQUATION OF SOME IRON(II) - PHENANTHROLINE COMPLEXES .2. INFLUENCE OF UREA AND SODIUM BENZOATE ON THE AQUATION OF FE(PH(2)PHEN)(3)(2+) IN ACETONE

The micelle-catalyzed aquation rates of iron(II) phenanthroline comple x Fe(Ph(2)Phen)(3)(2+) have been measured in aqueous acetone as solven t in the presence of urea and sodium benzoate as substrates. The varia tion patterns manifested by the estimated maximum catalytic factors an d k(o) vs [substrate] profiles show that the aquation rates of the com plex are inhibited by urea, while they are significantly enhanced by s odium benzoate. These observations have been rationalized by consideri ng the relative micelle bond-breaking capacities of the substrates, th e relative strengths of the H-bonds formed by the substrate/OH(-)headg roups of the micelle and the H2O/OH- headgroups of the micelle pairs.