Recombination kinetics of triplet radical ion pairs adsorbed onto microcrystalline cellulose studied by diffuse-reflectance laser flash photolysis

Langmuir ◽  
1993 ◽  
Vol 9 (4) ◽  
pp. 1001-1008 ◽  
Author(s):  
Peter P. Levin ◽  
L. F. Vieira Ferreira ◽  
Silvia M. B. Costa
Keyword(s):  
Microcrystalline Cellulose ◽  
Diffuse Reflectance ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Ion Pairs ◽  
Laser Flash ◽  
Kinetics Of ◽  
Recombination Kinetics

Geminate recombination kinetics of triplet radical ion pairs on silica studied by diffuse reflectance laser flash photolysis

1992 ◽  
Vol 193 (6) ◽  
pp. 461-468 ◽  
Author(s):  
Peter P. Levin ◽  
L.F. Vieira Ferreira ◽  
Silvia M.B. Costa ◽  
I.V. Katalnikov
Keyword(s):  
Diffuse Reflectance ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Ion Pairs ◽  
Laser Flash ◽  
Geminate Recombination ◽  
Kinetics Of ◽  
Recombination Kinetics

scholarly journals Surface photochemistry: Photodegradation study of pyrene adsorbed onto microcrystalline cellulose and silica

2004 ◽  
Vol 6 (4) ◽  
pp. 205-213 ◽  
Author(s):  
A. S. Oliveira ◽  
L. F. Vieira Ferreira ◽  
J. P. Da Silva ◽  
J. C. Moreira
Keyword(s):  
Radical Cation ◽  
Microcrystalline Cellulose ◽  
Ground State ◽  
Diffuse Reflectance ◽  
Transient Absorption ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Cation Radical ◽  
Laser Flash ◽  
Time Resolved

Ground-state diffuse reflectance, time resolved laser-induced luminescence, diffuse reflectance laser flash-photolysis transient absorption and chromatographic techniques were used to elucidate the photodegradation processes of pyrene adsorbed onto microcrystalline cellulose and silica. Ground-state diffuse reflectance showed that on both substrates low concentrations display absorption of pyrene monomers. At high concentrations spectral changes attributed to aggregate formation were observed. Laser induced fluorescence showed that pyrene onto microcrystalline cellulose mainly presents fluorescence from monomers, while for silica, excimer-like emission was observed from low surface loadings (≥0.5μmolg−1). Transient absorption and photodegradation studies were performed at concentrations where mainly monomers exist. On silica, pyrene presents transient absorption from its radical cation. On microcrystalline cellulose both radical cation, radical anion and pyrene triplet-triplet absorption were detected. Irradiation followed by chromatographic analysis showed that pyrene decomposes on both substrates. For pyrene on microcrystalline cellulose 1-hydroxypyrene was the main identified photoproduct since in the absence of oxygen further oxidation of 1-hydroxypyrene was very slow. For pyrene on silica photodegradation was very efficient. Almost no 1-hydroxypyrene was detected since in the presence of oxygen it is quickly oxidized to other photooxidation products. On both substrates, pyrene radical cation is the intermediate leading to photoproducts and oxygen it is not involved in its formation.

Kinetics of the 1,5-dipolar cyclization of 2-Vinylpyridinium ylides to Indolizines. Determination of rate parameters by laser flash photolysis

1994 ◽  
Vol 26 (12) ◽  
pp. 1179-1184 ◽  
Author(s):  
Michael T. H. Liu ◽  
Yuri N. Romashin ◽  
Roland Bonneau
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Kinetics Of

Kinetics of the Reaction of Electron Deficient Olefins with Nitrile Ylides Generated by Laser Flash Photolysis of Substituted Azirines

1983 ◽  
Vol 22 (8) ◽  
pp. 625-627 ◽  
Author(s):  
Nicholas J. Turro ◽  
David A. Hrovat ◽  
Ian R. Gould ◽  
Albert Padwa ◽  
William Dent ◽  
...  
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Kinetics Of

scholarly journals Kinetic studies of C1 and C2 Criegee intermediates with SO2 using laser flash photolysis coupled with photoionization mass spectrometry and time resolved UV absorption spectroscopy

2018 ◽  
Vol 20 (34) ◽  
pp. 22218-22227 ◽  
Author(s):  
N. U. M. Howes ◽  
Z. S. Mir ◽  
M. A. Blitz ◽  
S. Hardman ◽  
T. R. Lewis ◽  
...  
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Kinetic Studies ◽  
Laser Flash ◽  
Major Product ◽  
Time Resolved ◽  
Photoionization Mass Spectrometry ◽  
Criegee Intermediates ◽  
Wide Range ◽  
Kinetics Of

Kinetics of CH2OO + SO2 confirmed over a wide range of [SO2]. Acetaldehyde observed as a major product of the reaction of CH3CHOO + SO2.

scholarly journals Onium salts improve the kinetics of photopolymerization of acrylate activated with visible light

RSC Advances ◽  
2020 ◽  
Vol 10 (42) ◽  
pp. 24817-24829 ◽  
Author(s):  
Janina Kabatc ◽  
Katarzyna Iwińska ◽  
Alicja Balcerak ◽  
Dominika Kwiatkowska ◽  
Agnieszka Skotnicka ◽  
...  
Keyword(s):  
Steady State ◽  
Visible Light ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Chemical Mechanisms ◽  
Onium Salts ◽  
Nanosecond Laser Flash Photolysis ◽  
Kinetics Of

The chemical mechanisms were investigated by steady state photolysis and nanosecond laser flash photolysis experiments. A mechanism for initiating polymerization using both onium salts is proposed here.

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