Electrochromism in Electropolymerized Films of Pyrene-Triphenylamine Derivatives

Abstract

Two star-shaped multi-triphenylamine derivatives 1 and 2 were prepared, where 2 has an additional phenyl unit between a pyrene core and surrounding triphenylamine units. The oxidative electropolymerization of 1 and 2 occurred smoothly to give thin films of polymers P1 and P2. The electrochemistry and spectroelectrochemistry of P1 and P2 were examined, showing two-step absorption spectral changes in the near-infrared region. The electrochromic properties, including contrast ratio, response time, and cyclic stability of P1 and P2 were investigated and compared. Thin film of P2 displays slightly better electrochromic performance than P1, with a contrast ratio of 45% at 1475 nm being achieved.

Impact of the Replacement of a Triphenylamine by a Diphenylmethylamine Unit on the Electrochemical Behavior of Pentaerythritol‐Based Push‐Pull Tetramers

“…Electropolymerizable arylamine containing monomers can be achieved by exploiting the dimerization ability of two or more unsubstituted arylamine units connected to a central core, for example in star‐bust or multimeric systems. Different examples of electropolymerization of arylamine derivatives to produce modified electrodes are indeed reported in the literature, and have shown promising results when employed as electroactive polymer layers in electrochromic devices . Another attractive approach for the obtainment of functionalized triarylamine electroactive surface, as an alternative to electrodeposition from monomer solution, exploits the dimerizing ability of arylamine units just in a post deposition step of pre‐deposited films.…”

Electrochemistry and Electrochromic Performance of a Metallopolymer Formed by Electropolymerization of a Fe(II) Complex with a Triphenylamine‐Hydrazone Ligand

“…Further increase of the applied potential to 1.4 V resulted in the decrease of the intensity of bands characteristic for radical cation and it was concomitant with the formation and increase of intensity of broad absorption in the visible and partially NIR regions with the maxima at 770 nm. This was connected with the formation of TPB dication [14] . The change in the structure of the polymer during color change has been illustrated in Figure S6.…”

“…This was connected with the formation of radical cation arising from the oxidation of one of TPA groups form the TPB moiety [10] . The absorption band in the NIR region was connected with the presence of an intervalence charge transfer (IV‐CT) in the mixed‐valent state in TPB radical cation [10,14,50] . In addition, the isosbestic point was observed at ca.…”

“…Triphenylamine derivatives exhibit good thermal stability and reversible redox processes, and therefore they are widely used as active materials in many types of electronic devices, such as memory devices, [1–3] dye‐sensitized solar cells, [4,5] organic light emitting diodes, [6,7] sensors [8,9] and electrochromic devices [10–13] . The anodic oxidation of electroactive triphenylamine group is always associated with the perceivable color change and the electrogenerated radical cation can dimerize to form tetraphenylbenzidine (TPB) moiety, which can be more easily oxidized in comparison to the triphenylamine group and shows strong absorption in the near‐infrared region being the result of the intervalence charge transfer (IVCT) transitions in the mixed‐valent state of TPB radical cation [14] …”

Synthesis and Properties of Donor-Acceptor Type Electrochromic Materials Based on Triphenylamine and Quinoxaline

“…近年来, 有机电致变色材料已成为 电致变色研究领域中的重点研究对象之一. 其中, 有机 导电聚合物是最具代表性的有机电致变色材料之一, 如 聚芳胺、聚噻吩及聚吡咯类导电高分子材料等被广泛关 注 [16][17][18][19][20][21] . 为了进一步提升有机导电聚合物的电致变色性 能, 一种有效的策略就是在分子设计中引入电子给体-电子受体(D-A)结构, 能够有效缩短变色响应时间, 提 高循环稳定性等 [22][23] .…”