Fluorescence quenching of protonated β-carbolines in water and microemulsions: evidence for heavy-atom and electron-transfer mechanisms

2013 ◽  
Vol 12 (9) ◽  
pp. 1606 ◽  
Author(s):  
Souad A. Mousa ◽  
Peter Douglas ◽  
Hugh D. Burrows ◽  
Sofia M. Fonseca
Keyword(s):  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Heavy Atom ◽  
Transfer Mechanisms

Photooxidation of 9,10-diethoxyanthracene: mechanistic dichotomies between homogeneous solution and reverse micelle photoprocesses

1990 ◽  
Vol 68 (4) ◽  
pp. 612-619 ◽  
Author(s):  
R. J. DeVoe ◽  
M. R. V. Sahyun ◽  
E. Schmidt ◽  
D. K. Sharma
Keyword(s):  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Reverse Micelle ◽  
Photoinduced Electron Transfer ◽  
Reverse Micelles ◽  
Heavy Atom ◽  
Homogeneous Solution ◽  
Intersystem Crossing ◽  
Primary Mechanism ◽  
Atom Effect

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.

Formation of CT complexes and electron transfer from excited molecules of anthracene derivatives to methylviologen in aqueous and micellar media

1987 ◽  
Vol 52 (7) ◽  
pp. 1658-1665
Author(s):  
Viktor Řehák ◽  
Jana Boledovičová
Keyword(s):  
Electron Transfer ◽  
Complex Formation ◽  
Fluorescence Quenching ◽  
Rate Constant ◽  
Formation Constants ◽  
Dynamic Quenching ◽  
Micellar Media ◽  
Complex Formation Constants ◽  
Anthracene Derivatives ◽  
Ct Complexes

Disodium 1,5- and 1,8-anthracenedisulphonate (ADS) and 9-acetylanthracene form coloured CT complexes with methylviologen (MV2+) in aqueous and micellar media. The complex formation constants and molar absorptivities were determined by the Benesi-Hildebrandt method. In the fluorescence quenching, its static component plays the major role. The dynamic quenching component is determined by the rate constant of electron transfer from the S1 state of ADS to MV2+.

scholarly journals Modeling biofilms with dual extracellular electron transfer mechanisms

2013 ◽  
Vol 15 (44) ◽  
pp. 19262 ◽  
Author(s):  
Ryan Renslow ◽  
Jerome Babauta ◽  
Andrew Kuprat ◽  
Jim Schenk ◽  
Cornelius Ivory ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Extracellular Electron Transfer ◽  
Transfer Mechanisms

THEORETICAL STUDIES ON THE COUPLING INTERACTIONS AND SELF-EXCHANGE REACTION MECHANISMS IN THE COMPLEXES OF NO WITH ONH AND NOH

2008 ◽  
Vol 07 (03) ◽  
pp. 435-446 ◽  
Author(s):  
PING LI ◽  
XIAOYAN XIE ◽  
YUXIANG BU ◽  
WEIHUA WANG ◽  
NANA WANG ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Exchange Reaction ◽  
Reaction Mechanisms ◽  
Natural Bond Orbital ◽  
Theoretical Studies ◽  
Exchange Reactions ◽  
Electron Transfer Mechanism ◽  
Proton Coupled Electron Transfer ◽  
Planar Geometries ◽  
Transfer Mechanisms

The coupling interactions and self-exchange reaction mechanisms between NO and ONH (NOH) have been systematically investigated at the B3LYP/6-311++G** level of theory. All the equilibrium complexes are characterized by the intermolecular H-bonds and co-planar geometries. The cisoid NOH/ON species is the most stable one among all the complexes considered due to the formation of an N – N bond. Moreover, all the cisoid complexes are found to be more stable than the corresponding transoid ones. The origin of the blueshifts occurring in the selected complexes has been explored, employing the natural bond orbital (NBO) calculations. Additionally, the proton transfer mechanisms for the self-exchange reactions have been proposed, i.e. they can proceed via the three-center proton-coupled electron transfer or five-center cyclic proton-coupled electron transfer mechanism.

Electron transfer mechanisms

1998 ◽  
Vol 2 (2) ◽  
pp. 235-243 ◽  
Author(s):  
DN Beratan ◽  
SS Skourtis
Keyword(s):  
Electron Transfer ◽  
Transfer Mechanisms

Fluoreszenzlöschung alternierender und nicht-alternierender polycyclischer aromatischer Kohlenwasserstoffe durch Nitroverbindungen / Fluorescence Quenching of Alternant and Non-alternant Polycyclic Hydrocarbons by Nitro Compounds

1977 ◽  
Vol 32 (12) ◽  
pp. 1561-1563 ◽  
Author(s):  
M. Zander
Keyword(s):  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Excitation Energy ◽  
Reduction Potential ◽  
Nitro Compounds ◽  
Polycyclic Hydrocarbons ◽  
Electron Transfer Mechanism ◽  
Diffusion Controlled ◽  
Polycyclic Aromatic ◽  
Alternant Hydrocarbons

Abstract Fluorescence Quenching of Alternant and Non-alternant Polycyclic Hydrocarbons by Nitro Compounds Fluorescence quenching of polycyclic aromatic hydro­ carbons by nitromethane or nitrobenzene in fluid solutions is due to an electron transfer mechanism. The non diffusion controlled rate constant of quenching is very much greater for alternant than for non-alternant hydrocarbons with equal singlet excitation energy. This is explained by the known more positive reduction potential of non-alternant compared to alternant hydrocarbons.

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