Synthesis and electro-optical properties of new conjugated hybrid polymers based on furan and fluorene units

A novel series of hybrid monomers containing furan and fluorene units, namely 2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (FFF), 2,7-di(furan-2-yl)-9H-fluoren-9-one (FOF) and 2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan (FHF), was synthesized and their electrochemical polymerization was achieved via potential cycling. Optical and electrochemical properties of the polymers, poly(2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (PFFF), poly(2,7-di(furan-2-yl)-9H-fluoren-9-one) (PFOF) and poly(2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan) (PFHF), were investigated and it was found that polymer films exhibited quasi-reversible redox behavior (Epox = 0.92 V for PFFF, Epox = 1.08 V for PFOF and Epox = 0.99 V for PFHF) accompanied with a reversible electrochromic behavior, yellow to dark blue for PFFF, orange to green for PFOF and orange to green for PFHF. Their band gap values (Eg) were found to be 2.49, 2.32 and 2.61 eV for PFFF, PFOF and PFHF, respectively.

A series of hybrid monomers containing furan and fluorene units was synthesized and optical and electrochemical properties of their electrochromic polymers were investigated.Figure optionsDownload as PowerPoint slideHighlights
► Furan and fluorene based three monomers and their polymers were synthesized.
► Optical and electrochemical properties were investigated.
► All polymer films have p-type doping and exhibited electrochromic properties.