High-performance electrofluorochromic devices based on aromatic polyamides with AIE-active tetraphenylethene and electro-active triphenylamine moieties

Abstract

Novel electrochromic (EC) and aggregation-enhanced emission (AEE)-active triphenylamine (TPA)-based polyamides were prepared and fabricated into electrofluorochromic (EFC) devices.

Overview on the Recent Progress on Electrofluorochromic Materials and Devices: A Critical Synopsis

“…As reported above, small molecular systems based on triphenylamines and their derivatives show notable electrofluorochromic properties. [29,103,104] It is noteworthy to highlight that conjugated polyamides, [103,104,[106][107][108][109] polyimides, [109,110] and polyazomethines, [111] based on arylamine derivatives are also very promising materials for electrochemical fluorescence switching. After the pioneeristic works reported by Kuo and coworkers, many triphenylamine-based polymers were proposed, where the TPA moiety is generally integrated into the polymer backbone.…”

Electroluminochromic Materials: From Molecules to Polymers

“…Liou’s group also developed a series of EFC polyamides, P9a – c , bearing triphenylamine in the backbone and studied the effects of different substituents on the triphenylamine moieties (electron-withdrawing cyano group and electron-donating methoxy group), as well as the effects of different spacers (cyclohexyl and TPE) in the polymer chain [56]. Interestingly, P9b and P9c containing AIE-active TPE moieties exhibited a lower solid state ϕ f than cyclohexyl-containing P9a , which was due to the TPE moiety being a stronger electron-donor than cyclohexane, thus contributing to a greater overall PET effect.…”

“…Interestingly, P9b and P9c containing AIE-active TPE moieties exhibited a lower solid state ϕ f than cyclohexyl-containing P9a , which was due to the TPE moiety being a stronger electron-donor than cyclohexane, thus contributing to a greater overall PET effect. Electrochemical oxidation of the three polyamide films quenched their fluorescence as shown in Figure 15, with a response time of 8.6, 7.1, and 6.5 s, respectively [56]. Furthermore, by incorporating hexyl viologen (HV) into the thin film EFC devices, fluorescence switching contrast ratio of P9a , P9b , and P9c could be increased from 21, 13, and 10% to 51, 43, and 37%, respectively.…”

“…Photos showing the corresponding fluorescence changes of P9a ( g ), P9b ( h ), and P9c ( i ) on oxidation are as shown. Reproduced with permission from [56]. Copyright 2018, the Royal Society of Chemistry.…”

Electrofluorochromism of Surface-Confined Tetrazines Investigated on the Monolayer Scale

“…The topic has been reviewed recently, highlighting the large number of molecular compounds likely to show this property as well as the instrumental set-up developed to investigate the process [1][2][3][4][5] . Up to now, most of the experimental works have been devoted to molecules in solution 6 or more scarcely to bulk materials 7 and examples of electrofluorochromism in solid state remain very rare 8 despite its major interest to design high contrast devices [9][10] . The detection of the phenomenon is based on either spectrofluoelectrochemistry in thin layer electrochemical cells [11][12][13][14] or fluorescence microscopy (wide field 15 or confocal [16][17] ) and more recently STM 18 which allows downsizing the detection to the single molecule level.…”