The solubilities of 2,2'-bipyridyl (bipy), 1,lO-phenanthroline (phen), and their complexes [FeL3I2 + as perchlorates have been determined in water and methanol-water mixtures (up to 87 wt. % organic solvent) at 295 K. The changes in free energies of transfer, AG",, thus obtained have been coupled with the free energies of transfer for the reactions (i) and (ii) to determine the AG", values of the ions Hbipy+ (or Hphen+) m bipy (or phen) + H + 0)[Fe(bipy),]2+ {or [Fe(phen),]2+) + Fe2+ + 3 bipy (or phen)(ii)H+, Hbipy+, Hphen+, and Fe2+. The AGet(H+) values in methanol-water reported are qualitatively in good agreement with literature values, althouy h quantitative disagreement exists. Values of AGet(Fc2+) from water to methanol-water mixtures have also been calculated.