Photochemistry of substituted 1-naphthylmethyl esters of phenylacetic and 3-phenylpropanoic acid: radical pairs, ion pairs, and Marcus electron transfer

1993 ◽  
Vol 115 (6) ◽  
pp. 2180-2190 ◽  
Author(s):  
Dayal P. DeCosta ◽  
James A. Pincock
Keyword(s):  
Electron Transfer ◽  
Ion Pairs ◽  
Radical Pairs ◽  
Acid Radical ◽  
Naphthylmethyl Esters ◽  
Substituted 1

Internal return in the photochemistry of ring-substituted 1-(1-naphthyl)ethyl esters of phenylacetic acid

1995 ◽  
Vol 73 (6) ◽  
pp. 885-895 ◽  
Author(s):  
J.M. Kim ◽  
J.A. Pincock
Keyword(s):  
Electron Transfer ◽  
Transfer Rate ◽  
Experimental Error ◽  
Phenylacetic Acid ◽  
Radical Pair ◽  
Ion Pair ◽  
Ethyl Esters ◽  
Electron Transfer Rate ◽  
Radical Pairs ◽  
Substituted 1

The photochemistry in methanol of the esters 12a–d has been studied in order to determine the importance of internal return of both ion pair and radical pair intermediates. The efficiency of internal return, determined by monitoring 18O exchange between the alcohol and carbonyl oxygens, was shown to be substituent dependent, varying from approximately 10% for the 4,7-dimethoxy substrate to nearly 50% for the 4-cyano case. The corresponding ground state solvolysis reactions gave about 10% internal return and, within experimental error, were substituent independent. Internal return was also examined by racemization of the chiral center in 12a and 12d. In summary, these combined results reveal that internal return probably occurs mainly through a contact (not solvent-separated) radical pair. More important, internal return has little effect on previously calculated electron transfer rate constants for converting the radical pair to the ion pair. Therefore, the previously reported Marcus' correlations are valid. Keywords: photochemistry of benzylic esters, internal return, photosolvolysis, electron transfer, radical pairs.

scholarly journals Direct Femtosecond Observation of Tight and Loose Ion Pairs upon Photoinduced Bimolecular Electron Transfer

2009 ◽  
pp. 613-615
Author(s):  
Omar F. Mohammed ◽  
Katrin Adamczyk ◽  
Natalie Banerji ◽  
Jens Dreyer ◽  
Bernhard Lang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ion Pairs

Elektronentransfer und Ionenpaare, 15 [ 1– 3] Radikalanion und Radikal-Kontakt-Ionenpaare von Dimesityl-tetraketon / Electron Transfer and Ion Pairing, 15 [1-3] Radical Anion and Radical Ion Pairs of Dimesityl Tetraketone

1990 ◽  
Vol 45 (8) ◽  
pp. 1197-1204 ◽  
Author(s):  
H. Bock ◽  
P. Hänel ◽  
H.-F. Herrmann
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Temperature Dependent ◽  
Contact Ion Pairs

The radical anion of dimesityltetraketone (ERed, I = -0.40 V) is easily generated in THF by potassium mirror/[2.2.2]-cryptand reduction. Its contact ion pairs with Na⊕, Cs⊕ and Ba⊕⊕ counter cations, prepared in THF solution by single electron transfer from the respective metals, are characterized by their ESR/ENDOR spectra, which exhibit temperature-dependent metal couplings of aNa⊕ = 0.061 mT (190 K), aCs⊕ = 0.021 mT (190 K), and aBa⊕⊕ = 0.145 mT (295 K).

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