scholarly journals Mechanism for Fluorescence Quenching of Tryptophan by Oxamate and Pyruvate: Conjugation and Solvation-Induced Photoinduced Electron Transfer

2018 ◽  
Vol 122 (25) ◽  
pp. 6483-6490 ◽  
Author(s):  
Huo-Lei Peng ◽  
Robert Callender
2017 ◽  
Vol 41 (19) ◽  
pp. 10828-10834 ◽  
Author(s):  
A. R. Jose ◽  
A. E. Vikraman ◽  
K. Girish Kumar

Photoinduced electron transfer (PET)-mediated fluorescence quenching of CdTe/CdS quantum dots by pralidoxime (PAM).


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yusheng Shi ◽  
Tiexin Zhang ◽  
Xiao-Ming Jiang ◽  
Gang Xu ◽  
Cheng He ◽  
...  

Abstract Synergistic photoredox and copper catalysis confers new synthetic possibilities in the pharmaceutical field, but is seriously affected by the consumptive fluorescence quenching of Cu(II). By decorating bulky auxiliaries into a photoreductive triphenylamine-based ligand to twist the conjugation between the triphenylamine-based ligand and the polar Cu(II)–carboxylate node in the coordination polymer, we report a heterogeneous approach to directly confront this inherent problem. The twisted and polar Cu(II)–dye conjunction endows the coordination polymer with diode-like photoelectronic behaviours, which hampers the inter- and intramolecular photoinduced electron transfer from the triphenylamine-moiety to the Cu(II) site and permits reversed-directional ground-state electronic conductivity, rectifying the productive loop circuit for synergising photoredox and copper catalysis in pharmaceutically valuable decarboxylative C(sp3)–heteroatom couplings. The well-retained Cu(II) sites during photoirradiation exhibit unique inner-spheric modulation effects, which endow the couplings with adaptability to different types of nucleophiles and radical precursors under concise reaction conditions, and distinguish the multi-olefinic moieties of biointeresting steride derivatives in their late-stage trifluoromethylation-chloration difunctionalisation.


2019 ◽  
Vol 43 (2) ◽  
pp. 963-969 ◽  
Author(s):  
Qi Wang ◽  
Da Jun Liu ◽  
Li Li Cui ◽  
Xiao-Li Hu ◽  
Xin-Long Wang ◽  
...  

A novel pillared-layer Cd-MOF was synthesized as luminescent sensor for detection of nitroaromatic explosives with highly selective and recyclable properties. The study also shows that the photoinduced electron transfer and resonance energy transfer were possible mechanisms of fluorescence quenching.


1990 ◽  
Vol 68 (4) ◽  
pp. 612-619 ◽  
Author(s):  
R. J. DeVoe ◽  
M. R. V. Sahyun ◽  
E. Schmidt ◽  
D. K. Sharma

We have compared the photooxidation of the title compound, DEA, by diphenyliodonium salts in homogeneous acetonitrile (AN) and in heptane/AOT/water reverse micelle solutions. The reaction is efficient, which we attribute to rapid (ca. 10 ps) deethylation of the DEA radical cation, initially formed by photoinduced electron transfer. In AN, the electron transfer occurs from singlet excited DEA, but in reverse micelles it is gated by intersystem crossing to triplet DEA. Under these conditions, DEA fluorescence quenching by the iodonium cation may still be observed; we infer operation of the external heavy atom effect as the primary mechanism. Keywords: anthracene, electron transfer, reverse micelle, photochemistry, picosecond.


2009 ◽  
Vol 113 (31) ◽  
pp. 10825-10829 ◽  
Author(s):  
Sayantan Bose ◽  
Aruna B. Wijeratne ◽  
Aniket Thite ◽  
George A. Kraus ◽  
Daniel W. Armstrong ◽  
...  

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