Survey of recent advances of in the field of π-conjugated heterocyclic azomethines as materials with tuneable properties

Bolduc, Andréanne; Mallet, Charlotte; Skene, W. G.

doi:10.1007/s11426-012-4778-4

Cited by 48 publications

(61 citation statements)

References 150 publications

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“…More importantly,such supramolecular contacts would be beneficial for promoting lateral fluorophore interactions for ultimately generating smooth and homogenous fluorescent thin films. [19] It therefore should minimally fluoresce. We were therefore motivated to preparec onjugateda zomethinest hat couldp romote lateral intermolecular hydrogen bonds and other supramolecular contacts for fluorescencee nhancement.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen‐Bond and Supramolecular‐Contact Mediated Fluorescence Enhancement of Electrochromic Azomethines

Wałęsa‐Chorab

Tremblay

Skene

2016

Chemistry A European J

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An electronic push-pull fluorophore consisting of an intrinsically fluorescent central fluorene capped with two diaminophenyl groups was prepared. An aminothiophene was conjugated to the two flanking diphenylamines through a fluorescent quenching azomethine bond. X-ray crystallographic analysis confirmed that the fluorophore formed multiple intermolecular supramolecular bonds. It formed two hydrogen bonds involving a terminal amine, resulting in an antiparallel supramolecular dimer. Hydrogen bonding was also confirmed by FTIR and NMR spectroscopic analyses, and further validated theoretically by DFT calculations. Intrinsic fluorescence quenching modes could be reduced by intermolecular supramolecular contacts. These contacts could be engaged at high concentrations and in thin films, resulting in fluorescence enhancement. The fluorescence of the fluorophore could also be restored to an intensity similar to its azomethine-free counterpart with the addition of water in >50 % v/v in tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), and acetonitrile. The fluorophore also exhibited reversible oxidation and its color could be switched between yellow and blue when oxidized. Reversible electrochemically mediated fluorescence turn-off on turn-on was also possible.

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Section: Introductionmentioning

confidence: 99%

Hydrogen‐Bond and Supramolecular‐Contact Mediated Fluorescence Enhancement of Electrochromic Azomethines

Wałęsa‐Chorab

Tremblay

Skene

2016

Chemistry A European J

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“…[18][19][20][21][22] As a further step in our contribution of developing donor-acceptor conjugated systems based on BDF, we report here on the synthesis and the electronic properties of extended BDF-thiophene derivatives 1a-d (Scheme 1). The electron donor ability of the thiophene units was strengthened by hexyloxy groups while electron withdrawing pentafluorophenyl, cyano and butylacetate groups were grafted on the BDF units.…”

Section: Introductionmentioning

confidence: 99%

Extended benzodifuran–thiophene systems connected with azomethine junctions: synthesis and electronic properties

Moussallem

Gohier

Frère

2015

Tetrahedron Letters

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“…When prepared from electron donating monomers, the resulting materials have an alternating electron donor‐acceptor configuration. Such electronic push–pull systems are highly conjugated and they absorb boldly in the visible 8. Their discrete absorbances can additionally be tuned across the entire visible spectrum contingent on the degree of conjugation and the precursors used for their preparation, while having the advantage of being easy to prepare 8a, 9.…”

Section: Introductionmentioning

confidence: 99%

“…Such electronic push–pull systems are highly conjugated and they absorb boldly in the visible 8. Their discrete absorbances can additionally be tuned across the entire visible spectrum contingent on the degree of conjugation and the precursors used for their preparation, while having the advantage of being easy to prepare 8a, 9. This is in contrast to their counterparts prepared by conventional aryl–aryl coupling protocols that require extensive synthetic and purification protocols 4f, 10.…”

Section: Introductionmentioning

confidence: 99%

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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Survey of recent advances of in the field of π-conjugated heterocyclic azomethines as materials with tuneable properties

Cited by 48 publications

References 150 publications

Hydrogen‐Bond and Supramolecular‐Contact Mediated Fluorescence Enhancement of Electrochromic Azomethines

Hydrogen‐Bond and Supramolecular‐Contact Mediated Fluorescence Enhancement of Electrochromic Azomethines

Extended benzodifuran–thiophene systems connected with azomethine junctions: synthesis and electronic properties

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

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