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.

scholarly journals Heavy-atom-free BODIPY photosensitizers with intersystem crossing mediated by intramolecular photoinduced electron transfer

2020 ◽  
Vol 18 (1) ◽  
pp. 10-27 ◽  
Author(s):  
Mikhail A. Filatov
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Triplet State ◽  
Singlet Oxygen ◽  
Photoinduced Electron Transfer ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Donor Acceptor

This review discusses photoinduced electron transfer, triplet state formation from charge transfer states and singlet oxygen generation by heavy-atom-free BODIPY donor–acceptor dyads and dimers.

Enhancement of Reverse Intersystem Crossing in Charge‐Transfer Molecule through Internal Heavy Atom Effect

2021 ◽  
pp. 2104646
Author(s):  
Hyung Suk Kim ◽  
Ja Yeon Lee ◽  
Seongjun Shin ◽  
Wonkyo Jeong ◽  
Sang Hoon Lee ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Heavy Atom Effect ◽  
Atom Effect

Photoinduced electron transfer between quantum dots and pralidoxime: an efficient sensing strategy

2017 ◽  
Vol 41 (19) ◽  
pp. 10828-10834 ◽  
Author(s):  
A. R. Jose ◽  
A. E. Vikraman ◽  
K. Girish Kumar
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Photoinduced Electron Transfer ◽  
Cds Quantum Dots

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

Löschung der Perylen-Fluoreszenz durch Ag+ -Ionen / Quenching of the Perylene Fluorescence by Ag+-Ions

1983 ◽  
Vol 38 (6) ◽  
pp. 698-700 ◽  
Author(s):  
H. Dreeskamp ◽  
A. Läufer ◽  
M. Zander
Keyword(s):  
Triplet State ◽  
Dynamic Process ◽  
Aromatic Compounds ◽  
Heavy Atom ◽  
Silver Ions ◽  
Intersystem Crossing ◽  
Fluid Solution ◽  
Long Wavelength ◽  
Wavelength Emission ◽  
Atom Effect

The fluorescence of perylene in fluid solution (λ0.0 = 440 nm) is quenched by silver ions in a dynamic process according to a Stern-Volmer kinetics (kq = 2 · 109 [1 • mol-1 · sec-1], in ethanol at 295 K). Simultaneously an unstructured long-wavelength emission (λmax ≈ 470 nm) appears which we assign to a perylene/Ag+ exciplex. A similar emission is observed when other polvcyclic aromatic compounds (PAC) are used, whose fluorescence as in the case of perylene is not easily quenched in an external heavy atom effect by iodopropane (kq ≦ 106). In these cases the excited PAC/Ag+ complex is long-lived enough to emit fluorescence since the intersystem crossing to the triplet system is slow due to the absence of an energetically favorable accepting triplet state

An exceptionally long-lived triplet state of red light-absorbing compact phenothiazine-styrylBodipy electron donor/acceptor dyads: a better alternative to the heavy atom-effect?

2020 ◽  
Vol 56 (11) ◽  
pp. 1721-1724 ◽  
Author(s):  
Yuqi Hou ◽  
Qingyun Liu ◽  
Jianzhang Zhao
Keyword(s):  
Charge Transfer ◽  
Triplet State ◽  
Electron Donor ◽  
Heavy Atom ◽  
Red Light ◽  
Intersystem Crossing ◽  
Spin Orbital ◽  
Heavy Atom Effect ◽  
Donor Acceptor ◽  
Atom Effect

Heavy atom-free dyads showing a red light-absorbing and exceptionally long-lived triplet state based on a spin–orbital charge transfer intersystem crossing mechanism.

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