The synthesis and characterization are described for the complex salt [Ru(κ2-2,2′-N2C10H6{(CH2)3(CF2)5CF3}2-4,4′)(κ2-2,2′-N2C10H8)2][PF6]2, where one of the 2,2′-bipyridyl ligands bears terminal bis(perfluoralkyl) chains, the purpose of which is to exploit ‘like-dissolves-like’ intermolecular forces as an anchoring mechanism for the complex in Nafion™ membranes. TBAB-modified-Nafion™ thin films (sulfonic acid protons exchanged for NBun4+ cations) were cast or spin-coated onto electrodes and glass microscope slips, exposed to CH2Cl2 solutions of the complex and then examined by fluorimetry and cyclic voltammetry. Steady state and time-resolved luminescence analysis revealed quite different behavior in comparison with tris-2,2′-bipyridyl ruthenium in unmodified Nafion™ films. Exposure to methanol solutions indicated mitigation of the swelling effect of this solvent along with sustained structural integrity of the mediator complex among the various microenvironmental domains of the TBAB-modified-Nafion™ polymer. The dramatic leaching evident for samples of regular tris-2,2′-bipyridyl ruthenium dications in unmodified and modified Nafion™ films is not apparent for the new [Ru(κ2-2,2′-N2C10H6{(CH2)3(CF2)5CF3}2-4,4′)(κ2-2,2′-N2C10H8)2]2+/TBAB-modified-Nafion™-coated electrodes. Thus CVs of the latter show sustained peak current densities in excess of 1.0 mA cm−2 for the Ru3+/2+ couple and thus decent mediator retention over multiple potential cycles when exposed to mixed methanol–phosphate buffer solutions.
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