- Effective palladium-catalyzed synthesis of triarylethene-based molecules in aqueous solution
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Highly effective and selective Pd-catalyzed coupling reactions of 1,1-dibromo-1-alkenes with various arylboronic acids have been performed in aqueous solution under mild conditions. The method is simple, economic, and practical for the synthesis of triarylethene-based compounds. Copyright
- Zhu, Yan,Sun, Peng,Yang, Hailong,Lu, Linhua,Yan, Hong,Creus, Marc,Mao, Jincheng
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experimental part
p. 4831 - 4837
(2012/09/22)
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- Construction of extended π-conjugation systems utilizing novel multicarbene complexes of titanium
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Titanium-multicarbene complexes, namely organo-titanium species having a plurality of titanium-carbene complex substructures, were easily prepared by the reaction of aromatic nuclei possessing spatially separated thioacetal moieties with the titanocene(II
- Ogata, Akitoshi,Anno, Shintaro,Kurata, Takeshi,Xu, Song,Tsubouchi, Akira,Takeda, Takeshi
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p. 1715 - 1719
(2008/02/07)
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- Triarylethene-based extended π-systems: Programmable synthesis and photophysical properties
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(Chemical Equation Presented) On the basis of an efficient Pd-catalyzed triarylation to a vinylsilane platform, four types of structurally well-defined triarylethene-based extended π-systems have been prepared very rapidly. From a compound library constructed by the present method, it was possible to find a number of interesting fluorescent materials, as well as interesting fluorescent properties such as aggregation-induced enhanced emission. A useful method for the rapid synthesis and property evaluation has also been developed.
- Itami, Kenichiro,Ohashi, Youichi,Yoshida, Jun-Ichi
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p. 2778 - 2792
(2007/10/03)
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- Diarylamino groups as photostable auxofluors in 2-benzoxazolylfluorene, 2,5-diphenyloxazoles, 1,3,5-hexatrienes, 1,4-distyrylbenzenes, and 2,7-distyrylfluorenes
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The relationship of structure to optical spectral properties was determined for five types of fluors in a search for an optimum-wavelength shifter to be used as part of the detection systems for high-energy particles from accelerators. In a search for photostable fluors to serve as waveshifters in plastic fibers it was found that the wavelengths of interest, absorption max 410 ± 10 nm and fluorescence emission max 480 ± 20 nm, along with other properties, such as high solubility and short fluorescence decay time, could be obtained from fluorophors composed of aromatic rings and vinyl groups only by using amino groups as auxochromes to give bathochromic shifts of wavelengths. Since primary, monoalkyl, and dialkylamino groups were not sufficiently photostable, a number of fluorophores bearing diarylamino groups were investigated. Syntheses of the fluors made use of the Buchwald amination, an improved version of the Emmons-Horner reaction, and other common reactions. The fluor types were the following: a 2-benzoxazolyl-7-(4-diarylamino)fluorene 7, 2-(4-cyanophenyl)-5-(4-aminophenyl)oxazoles 14 and 20, 1,3,5-hexatrienes 24a-d and 26a-c, 1,4-distyrylbenzenes 31d-g and 32a-e, and 2,7-distyrylfluorenes 40a,d-e. The unsymmetrical fluors 7, 14, and 20 were not as bright as the best hexatrienes, distyrylbenzenes, and distyrylfluorenes, which were all symmetrical. Where the 1,6-diaryl-1,3,5-hexatrienes 24a-d had high fluorescence quantum yield (Φf), the 1,1,6,6-tetraryl-1,3,5-hexatrienes 26a-c had both lower ε and Φf. Where the 1,4-distyrylbenzenes 31d-g had high Φf, the 1,4-bis(2-phenylstyryl)benzenes 32a-e had (Φf = 0. Diarylamino groups as auxofluors conferred higher photochemical stability than dialkylamino groups on similar fluorophores. The 1,4-distyrylbenzenes 31d,e and the 2,7-distyrylfluorenes 40d,e had the most desirable properties overall, which included fast decay times of 2 ns. Computer simulations predicted absorption and emission wavelengths fairly well, but were of little help for the prediction of brightness, stability, Φf, or decay time.
- Kauffman, Joel M.,Moyna, Guillermo
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p. 839 - 853
(2007/10/03)
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