Spectral investigation of conjugated azomethines: A large palette of colors possible with acid and oxidant doping

Bolduc, Andréanne; Rivier, Lucie; Dufresne, Stéphane; Skene, W. G.

doi:10.1016/j.matchemphys.2011.12.002

Cited by 21 publications

(13 citation statements)

References 27 publications

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“…The chemically induced absorbance was hypsochromically shifted by 110 nm relative to electrochemically induced absorbance change. The observed difference is in part owing to the different counter ions that are known to impact the color 30. While the exact reason for the color difference cannot be unequivocally assigned, the collective chemical and electrochemical data nonetheless confirm that 3 can undergo both reversible and significant color changes upon oxidation.…”

Section: Resultsmentioning

confidence: 91%

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

Sicard

Navarathne

Skalski

et al. 2013

Adv Funct Materials

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An electroactive polyazomethine is prepared from a solution processable 2,5-diaminothiophene derivative and 4,4 ′ -triphenylamine dialdehyde by spraycoating the monomers on substrates, including indium tin oxide (ITO) coated glass and native glass slides. The conjugated polymer was rapidly formed in situ by heating the substrates at 120 ° C for 30 min in an acid saturated atmosphere. The resulting immobilized polymer is easily purifi ed by rinsing the substrate with dichloromethane. The on-substrate polymerization is tolerant towards large stoichiometry imbalances of the comonomers, unlike solution step-growth polymerization. The resulting polyazomethine is electroactive and it can be switched reversibly between its neutral and oxidized states both electrochemically and chemically without degradation. A transmissive electrochromic device is fabricated from the immobilized polyazomethine on an ITO electrode. The resulting device is successfully cycled between its oxidized (dark blue) and neutral (cyan/light green) states with applied biases of + 3.2 and − 1.5 V under ambient conditions without signifi cant color fatigue or polymer degradation. The coloration effi ciency of the oxidized state at 690 nm is 102 cm 2 C − 1 .2 was chosen as a complementary monomer for condensing with 1 . This was because the resulting polyazomethine ( 3 ) was expected to absorb more in the yellow region of the spectrum than its all-thiophene polyazomethine counterpart. [ 17 ] This is a result of large twist angles between the homoaryl moieties and the azomethines of 3 that limit its degree of conjugation. However, its charged state was expected to be signifi cantly colored because of intramolecular charge transfer courtesy of the electron rich triarylamine. [ 18 ] A bold color transition between the neutral and charged states was therefore expected for the electroactive 3 , resulting in a electrochromic material whose switching could easily be seen by the eye. This is a desired property for use in low-resolution and large area electrochromic display applications such as signs and billboards.The on-substrate polymerization of 3 was initially done using stoichiometric amounts of the complementary comonomers. These conditions were used because step-growth polymerization is known to be intolerant towards comonomer stoichiometric imbalances. [ 19 ] Only trimers and lower molecular weight oligomers are obtained when the molar ratio of the comonomers is varied by more than 1 mol%. The 1:1 mole ratio of 1 to 2 was further used to test the polymerization conditions required to produce 3 . Since this ratio was expected to yield 3 , the effect of the monomer concentration on the resulting comonomer and polymer fi lms deposited on the substrate could also be examined.The polymerization of 3 was done by spray-coating the premixed comonomer solutions onto glass substrates. The substrates were then heated between 60 and 150 ° C in a TFA saturated environment. TFA was chosen as the catalyst because of its high vapor pressure. A saturated acid atmosphe...

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Section: Resultsmentioning

confidence: 91%

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

Sicard

Navarathne

Skalski

et al. 2013

Adv Funct Materials

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“…Many heterocyclic Schiff bases show promising physical, chemical, and biological properties. An interest in the exploration of novel heteroaromatic azomethines has undoubtedly been growing due to their proven usefulness as attractive lead structures for the development of catalysts, intermediates in organic synthesis, dyes [ 7 ], pigments, polymer stabilizers [ 8 ], and corrosion inhibitors [ 9 ]. For example, a number of heteroaromatic imines containing a pyridine, thiophene, or furan ring were synthesized [ 10 ], demonstrating optical and electrochemical responses towards the acid environment.…”

Section: Introductionmentioning

confidence: 99%

“…H NMR (400 MHz, DMSO) δ 12.01 (1H, s, NH), 8.99 (1H, dd, J = 8.0, 1.1 Hz), 8.72 (1H, d, J = 8.0 Hz), 8.66 (1H, dd, J = 6.7, 1.1 Hz), 8.57 (1H, d, J = 8.0 Hz), 8.55 (1H, s), 8.31 (1H, dd, J = 7.8, 1.1 Hz),7.89 (1H, t, J = 7.8 Hz),7.82 (1H, td, J = 7.5, 1.1 Hz),7.57 (1H, t, J = 7.5 Hz),7.46 (1H, d, J = 8.0 Hz), 7.17 (1H, s), 6.85 (1H, d, J = 4.2 Hz), 6.28 (1H, d, J = 6.7 Hz);13 C NMR (100 MHz, DMSO) δ 183.2, 151.7, 151.5, 136.5, 134.3, 132.4, 131.4, 130.2, 130.1, 129.2, 128.3, 128.0, 127.7, 127.1,126.6, 125.5, 124.1, 122.9, 118.3, 114.3, 110.7; FTIR (KBr) ν max 3298, 3044, 1640, 1610, 1564, 1505, 1458, 1382, 1302, 1280, 1086, 1042, 970, 856, 780, 734, 602 cm −1 EIMS m/z 322 [M] + (89), 321 (100), 292 (14), 265 (8), 239 (6), 227 (12), 201 (18), 200 (22), 161 (14), 147 (16).3-[N-(Pyridin-4-ylmethylidene)amino]benzo[de]anthracen-7-one (2b). The product was obtained as an orange crystalline solid with a yield of 77%; mp 260-261 • C; 1 H NMR (400 MHz, DMSO) δ 8.95 (1H, s), 8.82-8.90 (4H, m), 8.72 (1H, dd, J = 7.0, 1.2 Hz), 8.66 (1H, d, J = 7.8 Hz), 8.36 (1H, dd, J = 7.8, 1.6 Hz), 8.02-8.07 (2H, m), 7.97 (1H, t, J = 7.8 Hz), 7.89 (1H, td, J = 7.8, 1.6 Hz), 7.62-7.68 (2H, m); 13 C NMR (100 MHz, DMSO) δ 189.3, 158.9, 150.9, 149.6, 142.5, 135.9, 133.4, 131.1, 130.7, 130.4, 128.4, 128.3, 128.1, 124.6, 122.8, 122.4, 113.5; FTIR (KBr) ν max 3028, 1640, 1595, 1569, 1382, 1317, 1280, 1218, 1084, 839, 781, 746, 701 cm −1 ; EIMS m/z 334 [M] + (100), 256 (16), 202 (12), 201 (27), 200 (25).…”

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confidence: 99%

Heterocyclic Schiff Bases of 3-Aminobenzanthrone and Their Reduced Analogues: Synthesis, Properties and Spectroscopy

et al. 2021

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New substituted azomethines of benzanthrone with heterocyclic substituents were synthesized by condensation reaction of 3-aminobenzo[de]anthracen-7-one with appropriate aromatic aldehydes. The resulting imines were reduced with sodium borohydride to the corresponding amines, the luminescence of which is more pronounced in comparison with the initial azomethines. The novel benzanthrone derivatives were characterized by NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The structure of three dyes was studied by the X-ray single crystal structure analysis. The solvent effect on photophysical behaviors of synthesized imines and amines was investigated. The obtained compounds absorb at 420–525 nm, have relatively large Stokes shifts (up to 150 nm in ethanol), and emit at 500–660 nm. The results testify that emission of the studied compounds is sensitive to the solvent polarity, exhibiting negative fluorosolvatochromism for the synthesized azomethines and positive fluorosolvatochromism for the obtained amines. The results obtained indicate that the synthesized compounds are promising as luminescent dyes.

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“…In organic and macromolecular chemistry, the azomethine unit represents a versatile functional group due to its ability to support the self-organization towards different mesophases, but also to generate dynamic materials via covalent dynamic chemistry [ 24 , 25 , 26 ] while having high thermal stability, semiconducting properties and the ability to form organic complexes [ 27 , 28 , 29 , 30 , 31 ]. Due to this, azomethine linkage, also known as the imine or Schiff base, is frequently used in the building of new multifunctional liquid crystal dimers [ 12 , 32 , 33 , 34 , 35 ].…”

Section: Introductionmentioning

confidence: 99%

Mesomorphic Behavior of Symmetric Azomethine Dimers Containing Different Chromophore Groups

Perju

Marin

2021

Molecules

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A series of new azomethine dimers was synthesized by the condensation reaction of flexible bis-benzaldehydes with four aromatic amines containing phenyl, naphthyl, anthracene and pyrene groups. Their right structure was confirmed by FTIR and 1H-NMR spectroscopy and their thermal properties were investigated by thermogravimetric analysis, differential scanning calorimetry and polarized light optical microscopy. A view on their photophysical behavior was gained by UV-vis and photoluminescence spectroscopy. The dimers containing pyrene and anthracene presented liquid crystalline behavior, while the other dimers were crystalline compounds. Two dimers containing pyrene moieties formed mesomorphic glasses and had intense luminescence, promising properties for applications in building optoelectronic devices.

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Spectral investigation of conjugated azomethines: A large palette of colors possible with acid and oxidant doping

Cited by 21 publications

References 27 publications

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

Heterocyclic Schiff Bases of 3-Aminobenzanthrone and Their Reduced Analogues: Synthesis, Properties and Spectroscopy

Mesomorphic Behavior of Symmetric Azomethine Dimers Containing Different Chromophore Groups

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