Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• the percentage of azulene in the polymer backbone. The thin films of these polymers exhibited electrochromism, where the color changed from yellowish green (neutral and reduced state) to greyish brown (oxidized state) with electrochromic contrasts of 17 and 13% for polymers 137 and 138, respectively

• 141–144 was low compared to all-azulene-carbazole polymer 140 due to the electron transfer from azulene to benzothiadiazole and, due to this, they exhibited better electrochromism. An electrochromic device (ECD) constructed with polymer 143 exhibited black to transmissive electrochromism with high

• reported azulene-containing homo- and copolymers have proven to be efficient functional materials for organic field-effect transistor (OFET), all-polymer solar cell (PSC) applications, and they can also exhibit NIR absorption and electrochromism, and electrical conductivity. However, the reports on

Experimental and computational electrochemistry of quinazolinespirohexadienone molecular switches – differential electrochromic vs photochromic behavior

• Eric W. Webb,
• Jonathan P. Moerdyk,
• Kyndra B. Sluiter,
• Benjamin J. Pollock,
• Amy L. Speelman,
• Eugene J. Lynch,
• William F. Polik and
• Jason G. Gillmore

Beilstein J. Org. Chem. 2019, 15, 2473–2485, doi:10.3762/bjoc.15.240

• photochromism results from a spirocyclic ring-opening or other isomerization which results in increased conjugation. Electrochromism is also of increasing materials relevance, e.g., for self-dimming automotive mirror and aircraft window darkening applications [6][7][8]. In electrochromic applications, the color

• small molecule organic electrochromism [6][7][9]. One example that combines photochromic and electrochromic behavior (the latter of an unusual sort) is the class of perimidinespirohexadienones 1 (PSHDs) whose synthesis, electrochemistry and UV–vis spectroscopy were reported by Minkin and co-workers [10

• potential; on the oxidative return wave the subsequent oxidations of the LW dianion to its radical anion and then its neutral state are observed. Thus, in this unusual system, electrochromism proceeds by the same sort of spirocyclic ring-opening as the photochromic rearrangement but occurs from the radical

Oxidative and reductive cyclization in stiff dithienylethenes

• Michael Kleinwächter,
• Ellen Teichmann,
• Lutz Grubert,
• Martin Herder and
• Stefan Hecht

Beilstein J. Org. Chem. 2018, 14, 2812–2821, doi:10.3762/bjoc.14.259

• double bond isomerization in addition to ring-closure, has been investigated. Electrochromism was observed in almost all cases, with the major pathway being the oxidatively induced cyclization of the open isomers. The influence of the ring size (to lock the reactive antiparallel conformation) as well as

• dithienylethenes bearing benzonitrile substituents an additional and rare reductive electrocyclization was observed. The mechanism underlying both observed electrocyclization pathways has been elucidated. Keywords: diarylethenes; electrochromism; molecular switches; (spectro)electrochemistry; Introduction

• cyclovoltammetry (CV) and spectro-electrochemistry (SEC) [33]. Our present study is aiming to: 1) elucidate the influence of possible double bond isomerization on the electrochromism of sDTEs; 2) explore the structural effect of varying ring size as well as electronic modification; and 3) contribute to the

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• . Interestingly, the colors of viologen can be tuned by introducing various substituents at the nitrogen sites [37]. The synthesis of 11 illustrates the ease of functionalizing viologen on both nitrogens and it can potentially be used for studying synergic electrochromism coupled with PEDOT [35]. Diethyl 2

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• ]. Except for P-16 and P-18, the polymers exhibit quasi reversible oxidation behaviour. A spectroelectrochemical study revealed that some of the polymers exhibited a reversible colour change between purple in the neutral state and a transparent greenish grey in the oxidized state. The electrochromism was