Aquation of tris-(1,10-phenanthroline)iron(II) complexes in aqueous ethanol and in aqueous formic acid

Abstract

Rates of aquation of tris-(1,10-phenanthroline)iron(II) complexes have been determined in series of aqueous ethanol and aqueous formic acid solvent mixtures. Variation of aquation rate with solvent composition for the 5-nitro- and 4,7-dimethyl complexes in the two series of solvents suggests that, in the favourable case of the electron-withdrawing nitro-substituent and of aqueous ethanol as solvent, bond-making between iron and incoming water is of some significance in transition-state formation. An attempt is made to extend the use of the Grunwald–Winstein concept of the relation between reactivity and solvating power of solvents to these inorganic systems.