Violene/Cyanine Hybrids as Electrochromics Part 2: Tetrakis(4-dimethylaminophenyl)ethene and Its Derivatives

Hünig, Siegfried; Kemmer, Martina; Wenner, Hermann; Barbosa, Frédérique; Gescheidt, Georg; Perepichka, Igor F.; Bäuerle, Peter; Emge, Andreas; Peters, Karl

doi:10.1002/1521-3765(20000717)6:14<2618::aid-chem2618>3.0.co;2-w

Cited by 76 publications

(5 citation statements)

References 6 publications

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“…In the introduction, it was briefly mentioned that in the series of diazinium ethenes developed by Hünig et al, an effect related to benzocondensation emerges, resulting in a shift of the reduction potentials to less negative values [ 4 , 5 ]. This can be attributed to the strongly π-accepting capabilities of the quinoline ring with respect to pyridine (lower LUMO and lower HOMO), and to the aromatic stabilization of the reduced form.…”

Section: Resultsmentioning

confidence: 99%

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An Integrated Theoretical/Experimental Study of Quinolinic–Isoquinolinic Derivatives Acting as Reversible Electrochromes

et al. 2017

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A series of compounds, featuring an ethenylic bridge and quinoline and isoquinoline end capping units possessing systematically varied substitution patterns, were prepared as molecular materials for electrochromic applications. The different structures were optimized in order to maximize the electrochromic contrast in the visible region, mostly by achieving a completely UV-absorbing oxidized state. Density functional theory (DFT) calculations are exploited in order to rationalize the correlation between the molecular structure, the functional groups’ electronic properties, and the electrochemical behavior. It is shown that the molecular planarity (i.e. ring/ring π conjugation) plays a major role in defining the mechanism of the electrochemical charge transfer reaction, while the substituent’s nature has an influence on the LUMO energy. Among the compounds here studied, the (E)-10-methyl-9-(2-(2-methylisoquinolinium-1-yl)-vinyl)-1,2,3,4-tetrahydroacri-dinium trifluoromethanesulfonate derivative shows the most interesting properties as an electrochromophore.

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Section: Resultsmentioning

confidence: 99%

“…Violenes probably are the best known examples of performing molecular materials, though with a relevant limit: their colored state is a radical. This has consequences in terms of environmental stability and durability [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

An Integrated Theoretical/Experimental Study of Quinolinic–Isoquinolinic Derivatives Acting as Reversible Electrochromes

et al. 2017

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“…Organic dyes such as cyanines, [1][2][3] squaliums, [4,5] and diimmoniums, [6,7] and organometallic complexes such as nickel dithiolenes [8] and phthalocyanines [9] show a narrow energy gap which has been attributed to a long-range π-conjugation based on the effective delocalization of N/O-based cations and charge-transfer (CT) interactions based on metal ions, respectively. Thus, they are known to exhibit near-infrared (NIR) absorption in the range of 700-2000 nm.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of NIR‐Absorbing Ability of Bis(diarylmethylium)‐Type Dicationic Dyes Based on an Ortho‐Substitution Strategy.

Harimoto

Suzuki

Ishigaki

2023

Chemistry A European J

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Electrochromic systems capable of switching nearinfrared (NIR) absorption are fascinating from the viewpoint of applications in the materials and life sciences. Although 11,11,12, (AQDs) with a folded form undergo one-stage two-electron oxidation to produce twisted dicationic dyes exhibiting NIR absorption, there is a need to establish a design strategy that can enhance the NIR-absorbing abilities of the corresponding dicationic dyes. In this study, we designed and synthesized a series of AQD derivatives with various substituents introduced at the ortho-position(s) of the 4-methoxyphenyl group. X-ray and spectroscopic analyses revealed that NIR-absorbing properties can be changed by introduction of the orthosubstituents. Thus, control of the steric and electronic effects of the ortho-substituents on the 4-methoxyphenyl groups was demonstrated to be an effective strategy for fine-tuning of the HOMO and LUMO levels for neutral AQDs and twisted dications, respectively, resulting in the modification of electrochemical and spectroscopic properties under an "ortho-substitution strategy".

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“…Tetraaryl-substituted ethylenes 4 1,2 and butadienes 5 2 are representative members of violene/cyanine-hybrid-type redox systems 2,3 exhibiting electrochromic behavior 4 (Scheme 1), the characteristics of which can be finely-tuned by changing the Ar 2 C end-groups (cyanine-parts). π-Extension of the violene-part is another method for modifying these properties, but simplely extended vinylogues 5 are not suitable due to their instability in the presence of oxygen and proton.…”

Section: Introductionmentioning

confidence: 99%

“…8 Intermolecular C-C bond formation at the methine carbons 9 also occurs upon oxidation of the corresponding m-isomer (m-6N-a), since effective conjugation does not occur between the two cyanine-dye parts. 8 During the course of our continuing studies on novel redox-based response systems, 10,11 a series of violene/cyanine-hybrids were designed, in which one (1), two (2), or three (3) thiophene-2,5-diyl units are inserted between the two Ar 2 C=CH end-groups 12 based on the above results. Compared with the p-quinodimethane skeleton, thienoquinoid-type D r a f t π-systems are less labile 13 due to the lower aromaticity of thiophene.…”

Section: Introductionmentioning

confidence: 99%

Bis(diarylethenyl)-thiophenes, -bithiophenes, and -terthiophenes: a new series of electrochromic systems that exhibit a fluorescence response

et al. 2017

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2,5-Bis(diarylethenyl)thiophenes (1) and their bithiophene (2) and terthiophene (3) homologues were designed as a new series of violene/cyanine-hybrid-type electrochromic materials. Alkoxyphenyl and dialkylaminophenyl groups are used, respectively, as the aryl group in the cyanine parts of 1/2/3O and 1/2/3N, which emit fluorescence in the neutral state but not in the oxidized state. Voltammetric analyses of 18 newly prepared electron donors show that they all undergo reversible two one-electron oxidations. Redox potentials, UV/Vis spectral features, and fluorescence quantum yields are important parameters for characterizing the present electrochromic behavior with a fluorescence response, and can be finely tuned by changing aryl groups in the cyanine part, the number of thiophene rings in the violene part, and the alkyl-chain length of the alkoxyphenyl or diaklylaminophenyl groups (R = CH 3 , C 8 H 17 , C 16 H 33 ), which makes this a versatile platform for the design of novel electrochromic materials. (Scheme 1), the characteristics of which can be finely-tuned by changing the Ar 2 C end-groups (cyanine-parts). π-Extension of the violene-part is another method for modifying these properties, but simplely extended vinylogues 5 are not suitable due to their instability in the presence of oxygen and proton. Thus, there is a growing need for methods to insert cyclic π-systems 6 such as a p-phenylene unit as in 1,4-bis[2,2-(4-dimethylaminophenyl)]ethenylbenzene p-6N-a, which was prepared as a stable molecule. 7 While it showed a reversible two-electron oxidation-wave in the voltammogram, the dicationic state was not stable enough for isolation and instead transformed into oligomeric polycations (Scheme 2) despite the stability of its p-quinod structure. 8 Intermolecular C-C bond formation at the methine carbons 9 also occurs upon oxidation of the corresponding m-isomer (m-6N-a), since effective conjugation does not occur between the two cyanine-dye parts. Keywords 8During the course of our continuing studies on novel redox-based response systems, 10,11 a series of violene/cyanine-hybrids were designed, in which one (1), two (2), or three (3) thiophene-2,5-diyl units are inserted between the two Ar 2 C=CH end-groups 12 based on the above results. Compared with the p-quinodimethane skeleton, thienoquinoid-type the thiophene sulfur atom (S) and the ipso carbon (C ipso ) of the aryl group (sum of the van der Waals radii: 3.50 Å) ( Fig. 2 and Table 1). The observed short contacts are highly likely to be associated with electronic interaction between σ* (C-S) and π (C ipso ), resulting in conformational stability for the observed geometries. According to the theoretical calculation (B3LYP/6-31G*) for 2/3O-a, a geometry similar to that found in the crystal was obtained by structural optimization (Table 1 and Figs. 1d-f), 22 which supports the notion described above. In the solid-state geometry of 1O-a, slight deformation of the violene π-system is caused by steric repulsion between the two inner aryl groups, ...

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Violene/Cyanine Hybrids as Electrochromics Part 2: Tetrakis(4-dimethylaminophenyl)ethene and Its Derivatives

Cited by 76 publications

References 6 publications

An Integrated Theoretical/Experimental Study of Quinolinic–Isoquinolinic Derivatives Acting as Reversible Electrochromes

An Integrated Theoretical/Experimental Study of Quinolinic–Isoquinolinic Derivatives Acting as Reversible Electrochromes

Enhancement of NIR‐Absorbing Ability of Bis(diarylmethylium)‐Type Dicationic Dyes Based on an Ortho‐Substitution Strategy.

Bis(diarylethenyl)-thiophenes, -bithiophenes, and -terthiophenes: a new series of electrochromic systems that exhibit a fluorescence response

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