Tracer diffusion of the tris(1,10-phenanthroline)iron(II) cation in aqueous salt solutions. Effect of hydrophobic interactions

Abstract

Tracer diffusion coefficients for the Fe(phen)₃²⁺ ion (phen = 1,10-phenanthroline) have been measured in aqueous solutions containing Ni(phen)₃SO₄, Bu₄NBr, MgSO₄ and NaBr, respectively, at 298.2 K. The diffusion coefficient–viscosity product, Dη, is found to decrease with increasing concentration of Ni(phen)₃SO₄, but the concentration dependence of Dη is very weak in other salt solutions. The results suggest the presence of cation–cation interactions between Fe(phen)₃²⁺ and Ni(phen)₃²⁺.