29636-96-2Relevant articles and documents
Pyridine-Spiropyran Derivative as a Persistent, Reversible Photoacid in Water
Halbritter, Thomas,Kaiser, Christoph,Wachtveitl, Josef,Heckel, Alexander
, p. 8040 - 8047 (2017)
A highly versatile water-soluble pyridine-spiropyran photoswitch is reported which functions as photoacid in a wide pH range. Under neutral conditions, the open-ring merocyanine (MC-) exists to 48% and closes quantitatively by irradiation with visible light, while the reverse reaction occurs rapidly in the dark or by irradiation at 340 nm. The different pKa of the pyridine nitrogen in the closed spiropyran (4.8) and open merocyanine form (6.8) leads to a reversible proton release in a pH range of 3-7. Only negligible hydrolytic decomposition was observed in the pH range from 1 to 12. The application of potentially harmful UV light can be circumvented due to the fast thermal ring-opening except for pH values below 3. Its photoacidic properties make this compound an effective pH-regulating photoswitch in water and enable controlled proton-transfer processes for diverse applications. Additionally, all of the involved protonated states of the compound exhibit discriminative fluorescence features within certain pH ranges, which even expands its utility to a light-controllable, pH-sensitive fluorophore.
Water soluble squaraine dyes for use as colorimetric stains in gel electrophoresis
Lynch, Daniel E.,Kirkham, Andrew N.,Chowdhury, Mohammed Z.H.,Wane, Elizabeth S.,Heptinstall, John
, p. 393 - 402 (2012)
Here we report that the difficulties encountered in the synthesis of a dual-pendant sulfonate bis(indolenine)squaraine dye can be overcome through the use of equimolar amounts of the common reaction catalyst, thus creating an organic salt between the sulfonate groups and the protonated catalyst. Thus, a range of water-soluble dyes can further be prepared, by simply altering the catalyst. Crystal structures of four subsequent derivatives, prepared in this manner, are reported and show that, although the squaraine moieties remain essentially planar, the packing lattices can vary significantly, and the expectation that both sulfonic acid groups will protonate a stoichiometric amount of the available organic base catalyst is also demonstrated by one structure to not be fully true. Two of the dyes, whose crystal structures are reported, proved to be suitable as colorimetric stains for protein separation in sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), and an optimal method for staining is reported. Results obtained for a fifth dye, crystal structure not obtained, are also reported. In all cases the results were compared against non-colloidal Coomassie Brilliant Blue (CBB) and it was found that the limit of detection for all squaraine derivatives examined were comparable with that of CBB although the resolution between protein bands was better. In addition, it was discovered that gels stained with the fifth dye (presented in this study) could be imaged in UV excitation/fluorescent imaging mode. The image robustness (or colour fastness) of all squaraines was found to be good for only a few hours.
A dual functional probe: Sensitive fluorescence response to H2S and colorimetric detection for SO32-
Chen, Sheng,Ma, Chao,Yuan, Mao-Sen,Wang, Wenji,Wang, Dong-En,Chen, Shu-Wei,Wang, Jinyi
, p. 85529 - 85537 (2016)
Hydrogen sulfide (H2S) and sulfite (SO32-) are two important sulfur-containing species that play different and important roles in industrial and biological processes. Accordingly, the development of efficient methods for simple, rapid, sensitive and selective monitoring of H2S and SO32- is of the utmost importance in both environmental and biological sciences. In this study, we developed a new dual functional probe NIR-DNP for discriminative detection of H2S and SO32-. This probe can sense H2S and SO32-via two different approaches, a significant near-infrared fluorescence enhancement and color change from purple to cyan induced by H2S as well as a visible color change from purple to colorless caused by SO32-. The detection limits of the probe NIR-DNP for H2S and SO32- in aqueous solutions were 36.53 nM and 33.33 nM, respectively. Competitive experiments demonstrated that the probe NIR-DNP had a high fluorescence selectivity for H2S and excellent colorimetric selectivity for SO32- over other analytes. The sensing mechanism of the probe toward H2S and SO32- was based on the H2S-induced thiolysis of dinitrophenyl ether and SO32--induced nucleophilic addition, respectively. Further investigation showed that the probe NIR-DNP could be used to develop an easy-to-prepare and easy-to-detect paper-based test strip for cheap and effective detection of SO32-. Also, the probe NIR-DNP has the potential to image exogenous and endogenous H2S in living cells.
A hemicyanine-based fluorescent probe for hydrazine detection in aqueous solution and its application in real time bioimaging of hydrazine as a metabolite in mice
Li, Tao,Liu, Jian,Song, Linjiang,Li, Zicheng,Qi, Qingrong,Huang, Wencai
, p. 3197 - 3200 (2019)
A hemicyanine-based fluorescent probe, Hcy-Ac, was developed for the specific detection of hydrazine. With good water solubility and high sensitivity, Hcy-Ac has been successfully applied for the monitoring of in situ hydrazine release during the metabolism of isoniazid in mice.
Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins
Dong, Kui,Li, Xiang-Sheng,Liu, Qiang,Wu, Li-Zhu,Yang, Biao
supporting information, (2022/03/17)
An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.
Light-Switchable Buffers
Berton, Cesare,Busiello, Daniel Maria,Zamuner, Stefano,Scopelliti, Rosario,Fadaei-Tirani, Farzaneh,Severin, Kay,Pezzato, Cristian
, p. 21737 - 21740 (2021/08/26)
A visible light-switchable buffer system based on a merocyanine photoacid is presented. Para-substitution of the indolium side with a methoxy group affords a compound suitable for making hydrolytically stable aqueous buffers whose pH can be tuned between 7 and 4 using 500 nm light.
An AIE-active dual fluorescent switch with negative photochromism for information display and encryption
Li, Zhize,Liu, Lulu,Liu, Yifei
, p. 9872 - 9881 (2021/06/15)
A negative photochromic molecular switch with AIE and two-color fluorescence conversion properties was synthesized. This molecular switch was constructed by connecting two propyl sulfonic acid modified spiropyrans with one tetraphenylethene covalently, an
