High efficiency electrochemiluminescence from polyaniline:ruthenium metal complex films

Electrochemiluminescent films have been formed by electrodepositing polyaniline, PANI, in the presence of [Ru(bpy)2PIC]2+; bpy is 2,2′-bipyridyl and PIC is (2,2′-bipyridyl)-2(4-carboxylphenyl) imidazo [4,5][1,10] phenanthroline. The homogeneous charge transport diffusion coefficient, DCT, for the Ru2+/3+ couple within the PANI film is 2.6 ± 0.9 × 10−10 cm2s−1. The large DCT facilitates a fast regeneration of Ru3+ and, coupled to a relatively rigid microenvironment, results in a high ECL intensity in the presence of tripropylamine as a co-reactant compared to [Ru(bpy)3]2+. Significantly, despite the conducting nature of the polymer backbone, the [Ru(bpy)2PIC]2+ loaded PANI has the highest efficiency, 1.00%, yet reported for a surface confined ruthenium complex. Keywords: Electrochemiluminescence, Polyaniline, Ruthenium