Study of the electron transfer between iron(III) and lanthanide bisphthalocyanines through a water-solvent interface, using a micro liquid-liquid electrode

Preliminary results are presented on the electron transfer from lutetium bisphthalocyanines, Lu[Pc](2) and Lu[(t-Bu)(4)Pc](2), to the hexacyanoferrate ion, Fe(III), across the liquid-liquid interface between dichloromethane (S) and water (W): Lu[(tBu)(4)Pc](2) (S) + Fe(CN)(6)(3-) (W) double left right arrow Lu[(tBu)(4)Pc](+)(2) (S) + Fe(CN)(6)(4-) (W) A liquid-liquid microinterface has been used that behaves like the solid microelectrodes. The diffusion regime is time dependent, being radial at low scan rates and linear when the potential exploration is faster than 0.1 V.s(-1). The electron transfer coefficient has been evaluated from a treatment of the results at a low scan rate: alpha = 0.65. The rate constant for the electron transfer, obtained from the peak separation of the cyclic voltammogram at different scan rates is k degrees = 2.3 x 10(-3) cm.s(-1).