Redox-active and fluorescent pyrene-based triarylamine dyes and their derived electrochromic polymers

Two triarylamine derivatives, DPPA-2(NHCO-TPA) and DPPA-2(NHCO-NPC), composed of a central diphenylpyrenylamine (DPPA) unit via amide groups linked to two triphenylamine (TPA) or N-phenylcarbazole (NPC) sides are developed as an electroactive precursor to prepare electrochromic films through electrochemical polymerization. The dilute solutions of these two DPPA-containing compounds showed notable fluorescence and solvatochromic shifts. Electroactive polymeric films could be electrodeposited on the ITO electrode surface by repetitive cyclic voltammetry scanning of their dichloromethane solutions containing dissolved 0.1 M tetrabutylammonium perchlorate (TBAP) between 0 and 1.5 V. The polymer films displayed multi-staged redox processes and color changes upon electrochemical oxidation. Spectroelectrochemistry and electrochromic switching stability of the polymers were investigated. Simple single-layer electrochromic devices were also fabricated and tested.