Solvent/substrate effects on the micelle-catalyzed aquation reactions of some iron(II) phenanthroline complexes, I. Influence of water and acid on the aquation of Fe(Ph2Phen)32+ in acetone

The effects of a substrate additive, H⁺ and solvents (water and acetone), on the micelle-catalyzed aquation of tris-(4,7-diphenyl-1, 10-phenanthroline)iron(II), Fe(Ph₂Phen)₃ ²⁺, have been investigated using^#Triton X-100 micelles. The k₀ vs. TX-100] profiles at fixed H₂O] are structured, exhibiting maxima. Catalytic factors of 46.6–171.7 are observed for 5.56×10⁻²≤H₂O] 55.60×10⁻² mol dm⁻³. On the other hand, at fixed H⁺], the k₀ vs. TX-100] exhibit broad maxima. The aquation reaction is inhibited by H⁺ and catalytic factors decrease rapidly and exponentially from 422.5 to 20.9 for 0.20×10⁻³≤H⁺]≤2.00×10⁻³ mol dm⁻³. The aquation is found to be faster (ca. 160–1200 fold) in acetone than in the aqueous medium depending on the added H₂O]. These observations are rationalized on the basis of a proposed modified lamellar structure for the Triton X-100 (TX-100) micelles in which direct substitution of water molecules into the coordination sphere of the complex occurs.