TRANSMEMBRANE RECTIFIED ELECTRON-TRANSFER THROUGH PI-CONJUGATED ELECTROACTIVE LANGMUIR-BLODGETT MONOLAYERS ON GOLD ELECTRODES

Novel amphiphiles with pi-conjugated electroactive groups, -[2-[4-[2-( 4-pyridyl)vinyl]phenyl]vinyl]pyridinium perchlorate (1), and 2-[4-[2-( 4-quinolyl)vinyl]phenyl]vinyl]quinolinium perchlorate (2), were design ed and synthesized. Both compounds formed expanded monolayers at air-w ater interfaces. The monolayers transferred on gold disk electrodes at 25 mN m-1 by the Langmuir-Blodgett technique (horizontal lifting meth od) show one electron reduction/oxidation couple: E(pa) = -0.86 V, E(p c) = - 1.08 V vs. SCE for 1/Au and E(pa) = -0.78 V, and E(pc) = -0.84 V vs. SCE for 2/Au. Rectified transmembrane electron transfer through the LB monolayers of 1 and 2 on gold electrodes to [Fe(CN)6]3- in aque ous solutions has been proved by cyclic voltammetry and potential-step chronocoulometry.