- Rational Design of Azothiophenes—Substitution Effects on the Switching Properties
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A series of substituted azothiophenes was prepared and investigated toward their isomerization behavior. Compared to azobenzene (AB), the presented compounds showed red-shifted absorption and almost quantitative photoisomerization to their (Z) states. Furthermore, it was found that electron-withdrawing substitution on the phenyl moiety increases, while electron-donating substitution decreases the thermal half-lives of the (Z)-isomers due to higher or lower stabilization by a lone pair–π interaction. Additionally, computational analysis of the isomerization revealed that a pure singlet state transition state is unlikely in azothiophenes. A pathway via intersystem crossing to a triplet energy surface of lower energy than the singlet surface provided a better fit with experimental data of the (Z)→(E) isomerization. The insights gained in this study provide the necessary guidelines to design effective thiophenylazo-photoswitches for applications in photopharmacology, material sciences, or solar energy harvesting applications.
- Heindl, Andreas H.,Wegner, Hermann A.
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- Original synthesis and spectroscopic study of thiophene triazine derivatives with enhanced luminescence properties
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A straightforward access to π-conjugated oligothiophenes bearing amino-rich groups was developed. Palladium-catalyzed C–H arylation applied in the main step of the synthesis allowed to couple 2-thiophenecarbonitriles and aryl bromides with moderate to excellent yields (35–93%). Then, to improve their basic fluorescence properties, these compounds were transformed into their 2,4-diamino-1,3,5-triazine derivatives, also with good to excellent yields (74–98%). UV-Visible absorption and fluorescence studies identified a strongly emissive molecule (fluorescence quantum yield: ΦF = 0.78 ± 0.05), which could find use in sensors for applications in biology and in material chemistry. We observed an antagonistic effect in the spectroscopic properties of oligothiophenes bearing 2,4-diamino-1,3,5-triazine, resulting in improved absorptive and emissive properties for more constrained structures having shorter oligothiophenes chains.
- Rodrigues, Alysson Duarte,Marcotte, Nathalie,Quignard, Fran?oise,Deabate, Stefano,Robitzer, Mike,Lerner, Dan A.
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- Near-infrared organic fluorescent material, preparation method and application thereof
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The invention discloses a 2-bis(5-(4-(diphenylamino)phenyl)thiophene-2-yl)dicyanoethylene near-infrared organic fluorescent material, a preparation method and application thereof, and belongs to the technical field of organic photoelectric materials. A trans-thienyl butadiene cyanide derivative is formed by introducing a thiophene group and a triphenylamine group on the basis of a novel trans- butadiene cyanide group; due to special properties of the thiophene group, band gap level and steric configuration of a compound can be regulated, the compound has larger T1 and T2 energy level difference and smaller delta EST on high energy level, a delayed effect is reduced, the utilization rate of excitons is increased, and the luminous efficiency is remarkably increased; the compound has very good thermal stability and very good chemical stability, an organic electroluminescence device prepared as a luminous layer has the characteristics of lower driving voltage, higher current efficiency, higher external quantum efficiency and the like, and very good electroluminescent performance is obtained.
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Paragraph 0058; 0059
(2018/10/19)
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- ARYL PIPERIDINE DERIVATIVES AS INDUCERS OF LDL-RECEPTOR EXPRESSION FOR THE TREATMENT OF HYPERCHOLESTEROLEMIA
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This invention relates to novel compounds which up-regulate LDL receptor (LDL-r) expression and to processes for their preparation, pharmaceutical compositions containing them and their medical use. More particularly, this invention relates to novel aromatic piperidines of formula (I) and their use in therapy.
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Page/Page column 53
(2008/06/13)
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- Palladium-Catalyzed Cyanation Reactions of Thiophene Halides
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The described method provides an efficient cyanation reaction of thiophene halides using tris(dibenzylidene-acetone)dipalladium(0), 1,1′-bis- (diphenylphosphino)ferrocene) and zinc powder as the catalyst system and Zn(CN)2 as the cyanide source
- Erker, Thomas,Nemec, Stephanie
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- Elimination reactions of (Z)-thiophene- and (Z)-furan-2-carbaldehyde O- benzoyloximes. Effect of β-aryl group upon the nitrile-forming anti transition state
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Elimination reactions of (Z)-thiophene- and (Z)-furan-2-carbaldehyde O- benzoyloximes 1 and 2 with DBU in MeCN have been investigated kinetically. The reactions are second order and exhibit substantial values of Hammett ρ and k(H)/k(D) values, and an E2 m
- Cho, Bong Rae,Cho, Nam Soon,Song, Sang Hun,Lee, Sang Kook
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p. 8304 - 8309
(2007/10/03)
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- Fluorescent bithiophene chromophores: synthesis and application in cd exciton chirality studies
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Bithiophene chromophores were synthesized and used to derivatize NH2 and OH groups in aminocyclohexane, (1R, 2R)-diaminocyclohexane, (1R, 2R)-trans-1,2-cyclohexanediol and methyl L-acosamidine for their application in the exciton chirality method. Schiff base, ester and amide derivatives were generated in good yields and were found to exhibit exciton-split CD curves. Besides their absorption at long wavelengths (red-shifted) in the visible range, the bithiophene derivatives showed fluorescence and solvatochromic properties.
- Ikemoto, Norihiro,Estevez, Isabel,Nakanishi, Koji,Berova, Nina
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p. 489 - 501
(2007/10/03)
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