Multifunctional polymers for electrochromic, memory device, explosive detection and photodetector: Donor-acceptor conjugated isoindigo derivatives with strong fluorescence

[Display omitted] •The polymer materials based on isoindigo, including electrochromic, memory device, explosive detection and photodetector.•The polymers show strong fluorescence with a fluorescence quantum efficiency (ФPL) of up to 32.5%.•The polymers exhibit good thermal stability, high electrochromic coloration efficiency, high performance memory device and fast response to TNT and TNP. We report here that a series of novel donor-acceptor (D–A) conjugated polymers based on isoindigo were synthesized and characterized. As novel electrochromic materials, their optical and electrochemical properties have been investigated. Cyclic voltammograms (CV) of the polymer films exhibit two pairs of obvious redox peaks in the range of 0.76–1.80 V with strong color changes in the visible and near infrared (NIR) regions. The coloring and bleaching time are in the range of 3.5–4.9 s and 4.4–5.0 s, respectively. The amount of char yield at 800 °C in nitrogen for polymers was in the range of 56–64%. Especially, the polymers show strong fluorescence with a fluorescence quantum efficiency (ФPL) of up to 32.5% which is reported firstly. In addition, memory properties, explosive detection and photoelectric properties for polymers are studied which indicating promising results.