Reactions of the excited singlet state of pyrene with metal ions. Intermolecular electron transfer in caffeine-solubilized aqueous solution

1981 ◽  
Vol 85 (10) ◽  
pp. 1353-1358 ◽  
Author(s):  
Yoshio Nosaka ◽  
Akira Kira ◽  
Masashi Imamura
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Metal Ions ◽  
Singlet State ◽  
Excited Singlet State ◽  
Intermolecular Electron Transfer ◽  
Excited Singlet

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.

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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