Multicolored Electrochromism of a Poly{1,4-bis[2-(3,4-ethylenedioxy)thienyl]benzene} Derivative Bearing Viologen Functional Groups

Abstract

1,4‐Bis[2‐(3,4‐ethylenedioxy)thienyl]‐2,5‐bis[6‐(1′‐butyl‐4,4′‐bipyridyl)hexyloxy]benzene tetrahexafluorophosphate (BEDOTPh‐2V) was synthesized and electropolymerized to form a viologen‐bearing conductive polymer [P(BEDOTPh‐2V)] film on an electrode surface. This polymer exhibits multicolor electrochromic behavior: it is highly transparent light‐blue P(BEDOTPh1.7+‐2V2+) at 1.0 V (vs. Ag/Ag+), pale‐bisque P(BEDOTPh0.6+‐2V2+) at 0.1 V, magenta P(BEDOTPh0‐2V2+) at –0.5 V, purple P(BEDOTPh0‐2V •+) at –0.9 V, and crimson P(BEDOT0‐2V0) at –1.4 V. Since both the viologen pendant and the polymer backbone have cathodic coloring characteristics and their redox‐potential ranges do not overlap each other, the dual electrochromic action provides more plentiful electrochromic colors compared to simple poly{1,4‐bis[2‐(3,4‐ethylenedioxy)thienyl]‐2,5‐dialkoxybenzene}.

Solid‐State Electrochromic Devices via Ionic Self‐Assembled Multilayers (ISAM) of a Polyviologen

“…[6,7,16] The main reasons these systems are not used in displays are their slow-switching speeds and inability to work in solid-state form. Lee et al [17,18] have studied the EC properties of polythiophene and polycarbazole derivatives with a viologen as a pendant unit by electropolymerization, but the whole process was tedious and expensive and there is no report of the device stability, which has been one of the main drawbacks of PV-based EC devices.…”

Synthesis, characterization, and redox and electrochromic behaviors of poly(3‐n‐octyloxythiophene)

“…Electrochromic materials have extensive applied prospects as intelligent materials and have been used for some devices. [1][2][3] In recent years, transition-metal oxides (e.g., WO 3 4,5 ), small organic molecules (e.g., viologen 6,7 ), some conducting polymers [e.g., Polypyrroles (PPys), 8 polyanilines, 9,10 and polythiophenes [11][12][13] have been intensively investigated for their electrochromic properties.…”

Influence of the Hofmeister series of anions on the molecular organization of positively ionized monolayers of a viologen derivative

“…Viologens are electroactive, being stable in at least three different oxidation states, and offer a significant electrochromic response. Viologens have found use in solar energy storage systems, as electron mediators in herbicides, and have been used to fabricate modified electrodes, bioelectronic devices, electrochromic writing paper, and molecular wires [12][13][14][15][16][17][18][19], amongst other applications [20][21][22][23][24]. The properties and consequently applications of viologens are sensitive to a variety of factors, including the nature of anions X − [12].…”