Polyconjugated azomethine layers by sequential condensation of a-a-dialdehyde- oligothiophenes and 4-4-diaminodiphenylenes on ITO/glass electrodes

Sequential (alternate) azomethine condensation of aldehyde end-capped oligothiophenes(Tn, n ) 3, 6, and 8) with p-diaminobiphenile (DAB) or p-diaminofluorene (DAF) on3-aminopropyltrimethoxysilane-primed (ATS- primed) ITO/glass is reported. The layers have been characterized by cyclic voltammetry, UV-vis spectroscopy, photoluminescence, XRD,and AFM. The oligothiophene layers first produced on the ATS-primed ITO are dense likeferrocene monolayers for T3 (4 x 10-10 mol cm-2) and ca. 3 times less dense for T6 and T8 (1.5 x 10-10 mol cm-2). The subsequent sequential growth occurs regularly with T3 but its rate is ca. 50% lower for T6 and almost null for T8. The condensed films are free of major defects and have the same roughness as the primed surface. Typical brush-electrodes formed by ATS/T3/(DAF/T3)4 and ATS/T6/(DAF/T6)2 sequences are fluorescent and reversibly protonated to colored films by perchloric acid in acetonitrile and undergo reversible iodinedoping.