Syntheses and properties of linear π-conjugated molecules composed of 1-azaazulene and azulene

Ohtsu, Keito; Hayami, Ryohei; Sagawa, Tadashi; Tsukada, Shinya; Yamamoto, Kazuki; Gunji, Takahiro

doi:10.1016/j.tet.2019.130658

Cited by 8 publications

(3 citation statements)

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“…Both PAzE-1 and PAzE-2 show a dual-band absorption in the range of 300–800 nm, which is attributed to the π–π* transition . In solution, the absorption bands centered at 562 nm for PAzE-1 and 572 nm for PAzE-2 are much red-shifted compared to those of M2 (Figure S5a), previously reported diazulenyl acetylenes − and model compounds H–H , H–T , and T–T in the range of 300–500 nm (Figure S6; their synthetic routes are shown in Scheme S4), demonstrating an extended π-conjugation length of PAzE-1 and PAzE-2 . Additionally, the absorptions of the two polymers centered at 562 and 572 nm, respectively, are obviously red-shifted in comparison with those of alkyl-substituted PPEs (the maximum absorption wavelength, λ max,abs = 387 nm) and 4,7-connected PAzE (λ max,abs = 456 nm), reflecting the effectiveness of 2,6-azulene units in extending π-conjugation.…”

Section: Resultsmentioning

confidence: 59%

Poly(2,6-azuleneethynylene)s: Design, Synthesis, and Property Studies

et al. 2022

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Two poly(2,6-azuleneethynylene)s (PAzE-1 and PAzE-2) were designed and synthesized. The 2,6-azulene units are head-to-tail-arranged in PAzE-1, while there are three types of orientations of 2,6-azulene units in PAzE-2: head-to-tail, head-tohead, and tail-to-tail segments, of which the head-to-tail one accounts for about 27% (determined from 1 H NMR spectra). Such a structural distinction endows the two polymers with different absorption spectra in solution and aggregation states as well as different thin-film morphologies, microstructures, and field-effect transistor (FET) performances, suggesting that the dipole orientation of azulene units in a polymer backbone may be a critical issue that deserves careful consideration during the molecular design and synthesis. PAzE-1 with an ordered dipole orientation has stronger aggregation even in a very dilute solution (10 −6 M). PAzE-2 films have a higher in-plane microstructural order and lower surface roughness than PAzE-1 films; hence, the PAzE-2-based transistor devices exhibit 1−2 orders higher hole and electron mobilities. Unlike typical p-type alkyl-substituted poly(pphenyleneethynylene)s (PPEs), PAzE-1 and PAzE-2 are ambipolar semiconductors.

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Section: Resultsmentioning

confidence: 59%

Poly(2,6-azuleneethynylene)s: Design, Synthesis, and Property Studies

et al. 2022

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“…The use of Au as an activating metal instead of Pd should be emphasized. The Sonogashira-Hagihara reaction afforded also the valuable compounds 45.1 [84] and 45.2 (Scheme 45) [85]. These linear π-conjugated molecules have optical properties and stimulus-responsive behavior.…”

Section: Scheme 44 Sonogashira-hagihara Reactionmentioning

confidence: 99%

Azulene, Reactivity, and Scientific Interest Inversely Proportional to Ring Size; Part 1: The Five-Membered Ring

Razus

2023

Symmetry

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The lack of azulene symmetry with respect to the axis perpendicular to a molecule creates an asymmetry of the electronic system, increasing the charge density of the five-atom ring and favoring its electrophilic substitutions. The increased reactivity of this ring has contributed to ongoing interest about the syntheses in which it is involved. The aim of this review is to present briefly and mainly in the form of reaction schemes the behavior of this system. After a short chapter that includes the research until 1984, subsequent research is presented as generally accepted chapters and subchapters to describe the behavior of the azulene system: metal free catalyst reactions; reactions catalyzed by metals; various azulene five-ring substitutions. The author insists on reaction yields, and in some cases considers it useful to present the proposed reaction mechanisms.

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“…6‐(1‐Azaazulen‐2‐yl)ethynylazulene ( 224 a ) and 6‐(2‐azulenyl)ethynylazulene ( 224 b ), were synthesized using the Sonogashira‐Hagihara cross‐coupling reaction of 6‐ethynylazulene 44 b with 2‐iodoazaazulenes 222 and 28 a , respectively, to give the corresponding diazulenylethyne 223 followed by decarboxylation with concentrated phosphoric acid (Scheme 48). [107] …”

Section: Reactions Of Ethynylazulenesmentioning

confidence: 99%

Alkynylazulenes as Building Blocks for Highly Unsaturated Scaffolds

Elwahy

Häfner

2021

Asian J Org Chem

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Recently developed routes to the synthesis of mono‐ and polyethynylated azulenes and their transformations into linear oligoazulenes with ethynyl and butadiynyl bridges as well as azulenyl‐substituted benzenes, cyclobutadiene complexes, and azulene‐substituted tetracyanobutadienes are reviewed. The utility of ethynylazulene derivatives for the synthesis of azulene‐substituted heterocycles has also been reviewed.

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Syntheses and properties of linear π-conjugated molecules composed of 1-azaazulene and azulene

Cited by 8 publications

References 47 publications

Poly(2,6-azuleneethynylene)s: Design, Synthesis, and Property Studies

Poly(2,6-azuleneethynylene)s: Design, Synthesis, and Property Studies

Azulene, Reactivity, and Scientific Interest Inversely Proportional to Ring Size; Part 1: The Five-Membered Ring

Alkynylazulenes as Building Blocks for Highly Unsaturated Scaffolds

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