scholarly journals Decarboxylation Rates of Benzoyloxyl Radicals as Determined by Laser Flash Photolysis. Further Insight into the Mechanism for Photodecomposition of Dibenzoyl Peroxides

1988 ◽  
Vol 17 (2) ◽  
pp. 357-360 ◽  
Author(s):  
Hiroaki Misawa ◽  
Ken Sawabe ◽  
Shigeru Takahara ◽  
Hirochika Sakuragi ◽  
Katsumi Tokumaru
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Insight Into

scholarly journals Benzylchlorocarbene: UV Absorption Spectrum, Kinetics for 1,2-H Migration and Mechanism for Reaction With Acetic Acid as Determined by Combined Continuous and Laser-Flash Photolysis

1990 ◽  
Vol 10 (5-6) ◽  
pp. 267-275 ◽  
Author(s):  
R. Bonneau ◽  
M. T. H. Liu ◽  
R. Subramanian ◽  
B. Linkletter ◽  
I. D. R. Stevens
Keyword(s):  
Absorption Spectrum ◽  
Acetic Acid ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Uv Absorption ◽  
Quenching Rate ◽  
Continuous Irradiation ◽  
Insight Into ◽  
Uv Absorption Spectrum

The UV absorption spectrum of benzylchlorocarbene, generated by laser flash photolysis of 3-chloro-3- benzyldiazirine, has been observed in the 290-330 nm range. The lifetime of this species, 18 ns at 25°C, is determined by the rate of the 1,2-H migration to produce chlorostyrenes. Quenching rate constants of this carbene by acetic acid and tetramethylethylene have been measured. Comparison of this kinetic data with the quantitative analysis of the products obtained under continuous irradiation gives further insight into the mechanisms of carbene-acetic acid reactions.

scholarly journals TiO2 Photocatalysis of the Organophosphorus Fenamiphos: Insight into the Degradation Mechanism

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
H. Mountacer ◽  
S. M. Nemmaoui ◽  
S. Rafqah ◽  
G. Voyard ◽  
M. Sarakha
Keyword(s):  
Titanium Dioxide ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Degradation Mechanism ◽  
Laser Flash ◽  
Order Rate Constant ◽  
Excitation Wavelength ◽  
Experimental Conditions ◽  
Positive Mode ◽  
Insight Into

The photocatalytic degradation of the organophosphorus fenamiphos (FN) was studied using titanium dioxide as a photocatalyst and 365 nm as an excitation wavelength. Under our experimental conditions and in aerated solutions, the irradiation in the presence of TiO2 P25 (1.0 g L−1) permitted the evaluation of the half lifetime to 9.5 minutes. Laser flash photolysis experiments showed the formation of an initial species owing to the attack of the hydroxyl radical on FN. It was identified as the adduct OH•-FN. The second order rate constant for its formation was evaluated to 7.3×109 moL−1 L s−1. All the products are formed via the formation of such transient intermediate. They were identified by means of HPLC/MS using electrospray in positive mode (ESI+). Two main processes are responsible for FN photocatalytic transformation: (i) hydroxylation on the aromatic structure and (ii) the scission of the C–O bond. A mechanistic scheme was proposed for the photocatalytic process of FN using titanium dioxide. An efficient mineralization was observed within 24 hours by using a suntest setup.

Effect of Aggregation on Bacteriochlorin a Triplet-state Formation: A Laser Flash Photolysis Study¶

2002 ◽  
Vol 76 (5) ◽  
pp. 480 ◽  
Author(s):  
Xavier Damoiseau ◽  
Francis Tfibel ◽  
Maryse Hoebeke ◽  
Marie-Pierre Fontaine-Aupart
Keyword(s):  
Triplet State ◽  
State Formation ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash

A Laser Flash Photolysis and Pulse Radiolysis Study of Primary Photochemical Processes of Flumequine¶

2000 ◽  
Vol 72 (4) ◽  
pp. 451 ◽  
Author(s):  
M. Bazin ◽  
F. Bosca ◽  
M. L. Marin ◽  
M. A. Miranda ◽  
L. K. Patterson ◽  
...  
Keyword(s):  
Pulse Radiolysis ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Photochemical Processes

Laser Flash Photolysis Studies of the UVA Sunscreen Mexoryl® SX

1999 ◽  
Vol 70 (3) ◽  
pp. 292
Author(s):  
Ann Cantrell ◽  
David J. McGarvey ◽  
Louise Mulroy ◽  
T. George Truscott
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash

Singlet Methylene Removal Rate Constants from the (0,1,0) Vibrational Level: Enhancement via Complex-Mediated Vibrational Relaxation

2001 ◽  
Vol 215 (6) ◽  
Author(s):  
M.A. Buntine ◽  
G.J. Gutsche ◽  
W.S. Staker ◽  
M.W. Heaven ◽  
K.D. King ◽  
...  
Keyword(s):  
Vibrational Level ◽  
Rate Constants ◽  
Vibrational Relaxation ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Removal Rate ◽  
Laser Flash ◽  
Laser Absorption ◽  
Photolysis Laser ◽  
Singlet Methylene

The technique of laser flash photolysis/laser absorption has been used to obtain absolute removal rate constants for singlet methylene,

Electron transfer sensitized photolysis of 'onium salts

1988 ◽  
Vol 66 (2) ◽  
pp. 319-324 ◽  
Author(s):  
R. J. DeVoe ◽  
M. R. V. Sahyun ◽  
Einhard Schmidt ◽  
N. Serpone ◽  
D. K. Sharma
Keyword(s):  
Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Quantitative Model ◽  
Intersystem Crossing ◽  
Single Electron Transfer ◽  
Onium Salts ◽  
Encounter Complex ◽  
Back Electron Transfer

We have studied the anthracene-sensitized photolyses of both diphenyliodonium and triphenylsulphonium salts in solution using both steady-state and laser flash photolysis techniques. Photoproducts, namely, phenylated anthracenes along with iodobenzene or diphenylsulphide, respectively, are obtained from both salts with quantum efficiencies of ca. 0.1 at 375 nm. We infer the intermediacy of diphenyliodo and triphenylsulphur radicals formed by single electron transfer from the singlet-excited anthracene. We have developed a quantitative model of this chemistry, and identify the principal sources of inefficiency as back electron transfer, which occurs at nearly the theoretically limiting rate, intersystem crossing from the initially formed sensitizer–'onium salt encounter complex, and in-cage radical recombination.

Phototransformations of bridgehead-substituted dibenzobarrelenes. Steady-state and laser flash photolysis studies

1987 ◽  
Vol 52 (25) ◽  
pp. 5512-5517 ◽  
Author(s):  
S. Pratapan ◽  
K. Ashok ◽  
D. R. Cyr ◽  
P. K. Das ◽  
M. V. George
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash
Sign in / Sign up

Export Citation Format

Share Document