2207-28-5Relevant academic research and scientific papers
Environment-sensitive fluorophores with benzothiadiazole and benzoselenadiazole structures as candidate components of a fluorescent polymeric thermometer
Uchiyama, Seiichi,Kimura, Kohki,Gota, Chie,Okabe, Kohki,Kawamoto, Kyoko,Inada, Noriko,Yoshihara, Toshitada,Tobita, Seiji
, p. 9552 - 9563 (2012)
An environment-sensitive fluorophore can change its maximum emission wavelength (λem), fluorescence quantum yield (φf), and fluorescence lifetime in response to the surrounding environment. We have developed two new intramolecular charge-transfer-type environment-sensitive fluorophores, DBThD-IA and DBSeD-IA, in which the oxygen atom of a well-established 2,1,3-benzoxadiazole environment-sensitive fluorophore, DBD-IA, has been replaced by a sulfur and selenium atom, respectively. DBThD-IA is highly fluorescent in n-hexane (φf=0. 81, λem=537 nm) with excitation at 449 nm, but is almost nonfluorescent in water (φf=0.037, λem=616 nm), similarly to DBD-IA (φf=0.91, λem=520 nm in n-hexane; φf=0.027, λem=616 nm in water). A similar variation in fluorescence properties was also observed for DBSeD-IA (φf=0.24, λem=591 nm in n-hexane; φf=0.0046, λem=672 nm in water). An intensive study of the solvent effects on the fluorescence properties of these fluorophores revealed that both the polarity of the environment and hydrogen bonding with solvent molecules accelerate the nonradiative relaxation of the excited fluorophores. Time-resolved optoacoustic and phosphorescence measurements clarified that both intersystem crossing and internal conversion are involved in the nonradiative relaxation processes of DBThD-IA and DBSeD-IA. In addition, DBThD-IA exhibits a 10-fold higher photostability in aqueous solution than the original fluorophore DBD-IA, which allowed us to create a new robust molecular nanogel thermometer for intracellular thermometry. Sensitive fluorophores: Two new environment-sensitive fluorophores, DBThD-IA and DBSeD-IA (see figure), are reported. Their photophysical and photochemical properties have been investigated by UV/Vis absorption, fluorescence, and phosphorescence spectroscopy, analysis of the fluorescence lifetimes and optoacoustic signals, and by performing photolysis experiments. DBThD-IA has successfully been used to develop a photostable fluorescent nanogel thermometer. Copyright
Halogenated method of aromatic compound
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Paragraph 0086-0089, (2021/11/10)
The invention belongs to the field of organic synthesis, and particularly relates to synthesis of aromatic halogens, in particular to arylamine. The invention discloses a synthesis method of a corresponding ortho-halogenated product from aromatic compounds such as carbazole and phenol. The method comprises the following steps: adding a metal sulfonate salt catalyst, aromatic amine, carbazole, phenol and other hydrogen - heteroatom-containing aromatic compound reaction substrates, a halogenation reagent and a reaction solvent at a specific reaction temperature. After the drying agent is dried, the yield of the reaction product and the nuclear magnetic characterization determining structure are determined by column chromatography. The reaction product yield is determined by gas chromatography. By adopting the method, under the cheap metal salt catalyst, a plurality of ortho-substituted brominated and chloro products can be obtained with moderate to excellent yield.
