- First Example of a Pyrylium Salt Dimerisation in Solution
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A pyrylium salt is capable of forming dimers in non-polar solvents at room temperature.The dimer, corresponding to a head-to-tail configuration in which the monomer dipole moments are parallel, has been characterized by its electronic absorption spectra, fluorescence spectra and its fluorescence lifetime.The dimer-monomer equilibrium constant is found to be 2.7 * 105 dm3 mol-1.
- Markovitsi, Dimitra,Jallabert, Colette,Strzelecka, Helena,Veber, Michele
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- Synthesis of Long Chain Malachite Green Leuco Base (LMGH) and Its Spectroscopic Study in Organic Solvents and Ionic Micellar Solutions
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The synthesis of long chain malachite green leuco base (LMGH) is reported.The absorption spectra of LMGH in different solvents seem to be independent of the solvent polarity (dielectric constant), while the emission spectra are dependent on it.Slight fluorescence self-quenching of LMGH in methanolic solution appears at a concentration of ca. 4*10-5 mol dm-3 and it becomes the dominant factor above 2*10-4 mol dm-3.The effect of the long chain on the basicity of LMGH relative to that of malachite green leuco base (MGH) can be revealed by the fluorescence quenchi ng of both compounds by Fe3+.The quenching process obeys a static type of mechanism, which is followed by an electron transfer of LMGH to Fe3+.The fluorescence quenching efficiency of micellized LMGH by Fe3+ is very dependent on the charge of the micelle, and is most effective in sodium dodecyl sulfate (SDS) micelle.The color appearance of the dye from LMGH upon mixing with Fe3+, is easily observed in methanol, but not in SDS micelle.The critical micelle concentrations (cmc) of anionic (SDS) and cationic (hexadecyltrimethylammonium chloride, CTAC) micelles have been estimated using LMGH as a probe.
- El-Shishtawy, Reda M.,Fukunishi, Koushi
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- Visible light-induced N-methyl activation of unsymmetric tertiary amines
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In the presence of methylene group, selective N-methyl activation of tertiary amines has been accomplished with the aid of visible light using organic photocatalyst under air. This protocol explores numerous aliphatic and aromatic substituted tetra-hydroquinoline analogues from various tertiary amines and maleimides. Furthermore, this approach was applied to activate the methyl group of N-methyl carbazole to generate the biologically active molecule.
- Perumal, Gopi,Kandasamy, Mohanraj,Ganesan, Balaji,Govindan, Karthick,Sathya, Harsha,Hung, Min-Yuan,Chandru Senadi, Gopal,Wu, Ya-Ching,Lin, Wei-Yu
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supporting information
(2021/01/09)
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- ALDEHYDE-SELECTIVE WACKER-TYPE OXIDATION OF UNBIASED ALKENES
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This disclosure is directed to methods of preparing organic aldehydes, each method comprising contacting a terminal olefin with an oxidizing mixture comprising: (a) a dichloro-palladium complex; (b) a copper complex; (c) a source of nitrite; under aerobic reaction conditions sufficient to convert at least a portion of the terminal olefin to an aldehyde.
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Paragraph 0219
(2014/10/29)
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- Formal anti-Markovnikov hydroamination of terminal olefins
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A new strategy to access linear amines from terminal olefin precursors is reported. This two-step, one-pot hydroamination methodology employs sequential oxidation and reduction catalytic cycles. The formal hydroamination transformation proceeds with excellent regioselectivity, and only the anti-Markovnikov product is observed. Up to 70% yield can be obtained from styrenes or aliphatic olefins and either primary or secondary aromatic amines. Additionally, the scope is broad with respect to the olefin and accommodates a variety of functionalities; we demonstrate that amines with removable aryl protecting groups may be utilized to allow access to a more diverse array of hydroamination adducts.
- Bronner, Sarah M.,Grubbs, Robert H.
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p. 101 - 106
(2014/01/06)
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- New fluorescent stains for protein detection in sodium dodecyl sulfate-polyacrylamide gels
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Highly sensitive new fluorescent stains for proteins in sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE) were developed by combining an environment sensitive fluorophore and a hydrocarbon tail for improved binding to SDS molecules associated with the proteins. The experimental results showed that these dyes bound to protein-SDS complexes with a concomitant emission increase upon binding.
- Hong, Soo Yeon,Jun, Hyunsook,Yoon, Seung Soo,Kang, Chulhun,Suh, Myungkoo
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p. 318 - 319
(2007/10/03)
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