SN1-type mechanism for the carbon-carbon bond cleavage of tetrakis(4-methylphenyl)ethanone cation radical. A laser flash photolysis study

1992 ◽  
Vol 33 (52) ◽  
pp. 8105-8108 ◽  
Author(s):  
Ryoichi Akaba ◽  
Masaki Kamata ◽  
Hirochika Sakuragi ◽  
Katsumi Tokumaru
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Bond Cleavage ◽  
Cation Radical ◽  
Laser Flash ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Steady-State and Laser Flash Photolysis Study of the Carbon−Carbon Bond Fragmentation Reactions of 2-Arylsulfanyl Alcohol Radical Cations

2004 ◽  
Vol 69 (24) ◽  
pp. 8323-8330 ◽  
Author(s):  
Enrico Baciocchi ◽  
Tiziana Del Giacco ◽  
Fausto Elisei ◽  
Maria Francesca Gerini ◽  
Andrea Lapi ◽  
...  
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Radical Cations ◽  
Laser Flash ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Fragmentation Reactions ◽  
Alcohol Radical

scholarly journals Generation of N,N-Di(4-bromophenyl)nitrenium Ion Under Acidic Conditions: Search for a Nitrenium Dication

2020 ◽  
Author(s):  
Andrea Zeppuhar ◽  
Daniel Falvey
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Cation Radical ◽  
Laser Flash ◽  
Strong Electron ◽  
Nitrenium Ion ◽  
Mechanistic Analysis ◽  
Separate Pathway ◽  
Acidic Conditions ◽  
Aqueous Conditions

The behavior of the N,N-di(4-bromophenyl)nitrenium ion under acidic aqueous conditions was examined via laser flash photolysis experiments. A long-lived species forms and can be assigned as the cation radical or the dication. This species is unreactive towards nucleophiles and reactive towards strong electron donors, consistent with a cation radical. Mechanistic analysis indicates its formation is through a separate pathway than that of the nitrenium ion, suggestive of a triplet mechanism.

Photoinduced electron transfer C—C bond cleavage reactions; oxidations and isomerizations

1984 ◽  
Vol 62 (3) ◽  
pp. 424-436 ◽  
Author(s):  
L. W. Reichel ◽  
G. W. Griffin ◽  
A. J. Muller ◽  
P. K. Das ◽  
Seyhan N. Ege
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Bond Cleavage ◽  
Radical Cations ◽  
Laser Flash ◽  
Time Resolved ◽  
Fragmentation Reactions ◽  
Oxidative Products

We have shown that radical cations generated by photoinduced electron transfer (ET) in 1,2-diarylethanes, aryl pinacols, and their derivatives undergo fragmentation reactions. In the presence of oxygen oxidative products are obtained. Time-resolved laser flash photolysis and other ancillary techniques have permitted us to define the mechanisms of certain oxidative processes observed.

Photochemistry of α-chloro- and α-bromoacetophenone. Determination of extinction coefficients for halogen–benzene complexes

1988 ◽  
Vol 66 (6) ◽  
pp. 1474-1478 ◽  
Author(s):  
W. G. McGimpsey ◽  
J. C. Scaiano
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Benzene Solution ◽  
Halogen Bond ◽  
Bond Cleavage ◽  
Laser Flash ◽  
Quantum Yields ◽  
Extinction Coefficients ◽  
Transient Data

The photochemical dehalogenation of α-haloacetophenones (Cl, Br) in benzene solution has been examined under conditions of continuous and pulsed laser irradiation. Product and quantum yield studies indicate that carbon-halogen bond cleavage occurs with quantum yields of 0.88 and 0.41 for α-chloro- and α-bromoacetophenone, respectively. These values are based on trapping studies in which the PhC(O)ĊH2 radicals produced photochemically are scavenged by hydrogen donors such as benzenethiol. Laser flash photolysis studies lead to intense transient signals due to benzene–halogen complexes. Combination of transient data and quantum yields lead to extinction coefficients of 1 800 and 23 700 M−1 cm−1 for the chlorine (490 nm) and bromine (550 nm) complexes, respectively.

CO-Bond Cleavage of Esters with a Naphthyl Group in the Higher Triplet Excited State during Two-Color Two-Laser Flash Photolysis

2007 ◽  
Vol 13 (11) ◽  
pp. 3143-3149 ◽  
Author(s):  
Xichen Cai ◽  
Masanori Sakamoto ◽  
Minoru Yamaji ◽  
Mamoru Fujitsuka ◽  
Tetsuro Majima
Keyword(s):  
Excited State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Bond Cleavage ◽  
Laser Flash ◽  
Triplet Excited State

scholarly journals Generation of N,N-Di(4-bromophenyl)nitrenium Ion Under Acidic Conditions: Search for a Nitrenium Dication

2020 ◽  
Author(s):  
Andrea Zeppuhar ◽  
Daniel Falvey
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Cation Radical ◽  
Laser Flash ◽  
Strong Electron ◽  
Nitrenium Ion ◽  
Mechanistic Analysis ◽  
Separate Pathway ◽  
Acidic Conditions ◽  
Aqueous Conditions

The behavior of the N,N-di(4-bromophenyl)nitrenium ion under acidic aqueous conditions was examined via laser flash photolysis experiments. A long-lived species forms and can be assigned as the cation radical or the dication. This species is unreactive towards nucleophiles and reactive towards strong electron donors, consistent with a cation radical. Mechanistic analysis indicates its formation is through a separate pathway than that of the nitrenium ion, suggestive of a triplet mechanism.

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