Excited Singlet State Reactions of Triphenylpyrylium Ion with Electron Donors:  Evidence for Electron Transfer and the Observation of Marcus Inverted Region for the Charge Shift in the Radical Pair

1997 ◽  
Vol 101 (11) ◽  
pp. 2016-2022 ◽  
Author(s):  
S. S. Jayanthi ◽  
P. Ramamurthy
Keyword(s):  
Electron Transfer ◽  
Singlet State ◽  
Radical Pair ◽  
Electron Donors ◽  
Excited Singlet State ◽  
Excited Singlet ◽  
Inverted Region ◽  
Marcus Inverted Region ◽  
Charge Shift

Photochemistry of Nitracrine and its Analogues: Acridine Derivatives as Electron Donors

1984 ◽  
Vol 39 (2) ◽  
pp. 195-200 ◽  
Author(s):  
J. Biedrzycki ◽  
J. Błażejowski ◽  
J. Szychliński ◽  
A. Ledòchowski
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Fluorescence Quenching ◽  
Triplet State ◽  
Uv Radiation ◽  
Electron Acceptor ◽  
Singlet State ◽  
Electron Donors ◽  
Excited Singlet State ◽  
Excited Singlet

Studies on the electron transfer in the excited state from electron donors: acridine, 9- aminoacridine and its derivatives, including nitracrine and its isomers, to CCl4 as a suitable electron acceptor, were undertaken. UV radiation (λ= 366 nm), absorbed only by acridine bases, generates CI- ions. The fluorescence quenching measurements indicate that no interaction appears between molecules of acridine bases in the excited singlet state and CCl4 molecule. A scheme of photochemical processes is proposed which assumes that the triplet state of the base molecule is the reactive one.

scholarly journals The photochemistry of 1-naphthylmethyl carbonates and carbamates

1994 ◽  
Vol 72 (5) ◽  
pp. 1254-1261 ◽  
Author(s):  
T. Parman ◽  
J.A. Pincock ◽  
P.J. Wedge
Keyword(s):  
Electron Transfer ◽  
Singlet State ◽  
Radical Pair ◽  
Ion Pair ◽  
Excited Singlet State ◽  
Excited Singlet ◽  
Homolytic Cleavage ◽  
Product Yields ◽  
Oxygen Bond

The photochemistry in methanol of 1-naphthylmethyl phenyl carbonate (3) and 1-naphthylmethyl benzyl carbonate (4) has been studied. Products resulting from both the 1-naphthylmethyl cation and the 1-naphthylmethyl radical are obtained for 3, but only from the cation for 4. Similar results were obtained for the corresponding 1-naphthylmethyl derivatives 5 and 6 of N-phenyl and N-benzyl carbamic acids. The product yields for all four compounds can be explained by a mechanism of initial homolytic cleavage of the 1-naphthylmethyl carbon–oxygen bond from the excited singlet state. The radical pair generated then partitions between the two pathways: electron transfer to form the ion pair or decarboxylation. For PhO-CO-O• and PhNH-CO-O•, decarboxylation is rapid and competitive with electron transfer. For PhCH2O-CO-O• and PhCH2NH-CO-O•, decarboxylation is slower, electron transfer dominates, and only products from the ion pair are obtained.

Photolysis of the 1-naphthylmethyl ester of substituted phenylacetic acids: intramolecular charge transfer and rates of decarboxylation of arylacyloxy radicals

1992 ◽  
Vol 70 (3) ◽  
pp. 992-999 ◽  
Author(s):  
James W. Hilborn ◽  
James A. Pincock
Keyword(s):  
Electron Transfer ◽  
Singlet State ◽  
Intramolecular Charge Transfer ◽  
Radical Pair ◽  
Product Distribution ◽  
Intramolecular Electron Transfer ◽  
Naphthalene Ring ◽  
Excited Singlet ◽  
Homolytic Cleavage ◽  
Oxygen Bond

The photolysis of esters 6 and 8 in methanol leads to products resulting from both naphthylmethyl cations and radicals. The product distribution is nearly independent of X for the esters 6 except when X equals methoxy. A mechanism involving initial homolytic cleavage of the carbon–oxygen bond in the excited singlet state of the ester is proposed. Competition between electron transfer in the radical pair to form the ion pair and decarboxylation of the arylacyloxy radical allows calculations of the rates for this decarboxylation process. The ρ value versus σ is close to zero. When X equals methoxy, intramolecular electron transfer occurs with the naphthalene ring serving as the acceptor and the methoxyaromatic as the donor. This exciplex fragments to carbon dioxide and 1-(1-naphthyl)-2-arylethane. Keywords: acyloxy radical, decarboxylation, photolysis of benzylic esters.

Time-resolved electron transfer from the excited singlet state of anchored perylene into Ag(110)

2007 ◽  
Vol 449 (1-3) ◽  
pp. 82-85 ◽  
Author(s):  
Lars Gundlach ◽  
Frank Willig
Keyword(s):  
Electron Transfer ◽  
Singlet State ◽  
Excited Singlet State ◽  
Excited Singlet ◽  
Time Resolved

Electron-transfer reactions in the Marcus inverted region. Charge recombination versus charge shift reactions

1989 ◽  
Vol 111 (5) ◽  
pp. 1917-1919 ◽  
Author(s):  
Ian R. Gould ◽  
Jacques E. Moser ◽  
Bruce Armitage ◽  
Samir Farid ◽  
Joshua L. Goodman ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Recombination ◽  
Transfer Reactions ◽  
Inverted Region ◽  
Electron Transfer Reactions ◽  
Marcus Inverted Region ◽  
Charge Shift

Electrochemiluminescence of Phenanthrene-d10: A Possible Case of Efficient Triplet–Triplet Annihilation

1975 ◽  
Vol 53 (1) ◽  
pp. 76-78 ◽  
Author(s):  
N. Periasamy ◽  
K. S. V. Santhanam
Keyword(s):  
Electron Transfer ◽  
Transfer Reaction ◽  
Singlet State ◽  
Electron Transfer Reaction ◽  
Excited Singlet State ◽  
Excited Singlet ◽  
Triplet Triplet Annihilation

Electrochemiluminescence (e.c.1.) of mixed phenanthrene(Ph)-d10-oxidant and Ph-h10-oxidant systems have been studied. Emission from excited singlet state of Ph-d10 or Ph-h10 is observed. On the basis of energetics of the electron transfer reaction, triplet-triplet annihilation is postulated to give the excited singlet state of Ph. Comparison of these results with photoluminescence of Ph-d10, shows efficient triplet–triplet annihilation occurs in e.c.1.

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