Triplet electron transfer and time-resolved EPR: Detection of the radical-pair state of a covalently linked porphyrin—quinone

1991 ◽  
Vol 180 (3) ◽  
pp. 191-197 ◽  
Author(s):  
F. Lendzian ◽  
B. von Maltzan
2003 ◽  
Vol 81 (6) ◽  
pp. 789-798 ◽  
Author(s):  
Guilford Jones II ◽  
Xiaochun Wang ◽  
Jingqiu Hu

The electron-transfer photochemistry of rhodamine 6G thiocyanate ion pairs has been investigated. For dye in a low polarity solvent, such as ethyl acetate, the emission of rhodamine 6G is significantly quenched by thiocyanate counterions. Laser photolysis of rhodamine 6G and thiocyanate in ethyl acetate was studied in detail with the identification of the reduced rhodamine 6G radical species (λmax = 410 nm). The growth and decay of the R6G radical could be accounted for in part by a mechanism involving initial formation of dye triplet followed by electron transfer which provides a triplet radical-pair state on a µs timescale.Key words: electron transfer, ion pair, rhodamine 6G, triplet state.


1997 ◽  
Vol 101 (8) ◽  
pp. 1437-1443 ◽  
Author(s):  
A. van der Est ◽  
T. Prisner ◽  
R. Bittl ◽  
P. Fromme ◽  
W. Lubitz ◽  
...  

1983 ◽  
Vol 105 (9) ◽  
pp. 2903-2904 ◽  
Author(s):  
Michael R. Wasielewski ◽  
Christian H. Bock ◽  
Michael K. Bowman ◽  
James R. Norris

2013 ◽  
Vol 17 (06n07) ◽  
pp. 501-510 ◽  
Author(s):  
Maxence Urbani ◽  
Samira Osati ◽  
Susanne Kuhri ◽  
Dirk M. Guldi ◽  
Tomás Torres

A non-covalent supramolecular complex combining porphyrin (Por), phthalocyanine (Pc) and fullerene [ C 60], was obtained through zinc metal-pyridine coordination between a covalently meso-linked heterodimer ZnPor-ZnPc (4) and a N-pyridylfulleropyrrolidine derivative (5). The complexation was studied in toluene by absorption and fluorescence binding studies, and evidenced that the coordination of the N-pyridylfulleropyrrolidine (5) occurs preferentially through the zinc ion center of ZnPc (log K > 6.0) rather than ZnPor (log K = 5.23). Steady-state and time-resolved spectroscopies evidenced that upon selective excitation of either the Por, or the Pc moiety in [( ZnPor-ZnPc )∪ C 60], the singlet excited state of Pc was generated efficiently in both cases (either from singlet-singlet energy transfer from 1Por* to Pc, or directly after selective excitation of the Pc moiety). Next, an electron transfer occurred from the 1Pc* to the C 60 to generate the charge-separated specie [( ZnPor-ZnPc •+)∪ C 60•-]. Finally, the back electron transfer afforded the Pc triplet excited state rather than the ground state. The introduction of a covalent meso-linkage between Por and Pc in the heterodimer 4 and in the supramolecular assembly 4∪5 induces appreciable differences toward the photo-induced processes and the binding constants in comparison with other β-covalently linked analogue systems.


2018 ◽  
Vol 54 (48) ◽  
pp. 6148-6152 ◽  
Author(s):  
Mirco Natali ◽  
Agnese Amati ◽  
Nicola Demitri ◽  
Elisabetta Iengo

A surprisingly long-lived radical pair state is achieved in a tin-porphyrin/l-tyrosine conjugate by exploiting a photochemical PCET quenching mechanism.


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