Transport properties of copper(I) perchlorates in mixed solvents. Part 2.—Conductance and viscosity measurements of bis(2,9-dimethyl-1, 10-phenanthroline)copper(I) perchlorate in binary solvent mixtures containing acetonitrile

Abstract

Conductance and viscosity of bis(2,9-dimethyl-1, 10-phenanthroline)copper(I) perchlorate ([Cu(DMphen)2]ClO4) have been measured in the concentration range (0.6–6)× 10–4 mol dm–3 and (6–250)× 10– mol dm–3, respectively, at 25 °C in acetonitrile–water (AN–H2O), acetonitrile–methanol (AN–MeOH), acetonitrile–acetone (AN–AC) and acetonitrile–N,N-dimethylformamide (AN–DMF) mixtures containing 100, 90, 80, 70, 60, 50, 40, 30, 20, 10 and 0 mol% acetonitrile. The conductance and viscosity data have been analysed by the Shedlovsky and Jones–Dole equations, respectively. The limiting ion conductances of the [Cu(DMphen)2]+ cation in various solvent systems have been evaluated by combining Λo values of [Cu(DMphen)2]ClO4 with the accurate λClO4–O values obtained from our previous studies. The viscosity B coefficients of the salt in various solvent systems have been evaluated and split into the component contributions of [Cu(DMphen)2]+ and ClO–4 ions. The solvated radius (ri) for the [Cu(DMphen)2]+ cation in AN–H2O, AN–MeOH, AN–AC and AN–DMF mixtures remains nearly constant, indicating the same extent of solvation in all of these solvent systems. The solvation of this cation is, however, stronger in pure AN than in mixed solvents.