DIRECT PHOTOLYSIS AT 185 NM OF CYCLOPENTENE AND 2-NORBORNENE. A NOVEL REACTION CHANNEL FOR π,π*EXCITED SINGLET ALKENE

1982 ◽  
Vol 11 (7) ◽  
pp. 1045-1048 ◽  
Author(s):  
Yoshihisa Inoue ◽  
Toshio Mukai ◽  
Tadao Hakushi
Keyword(s):  
Reaction Channel ◽  
Excited Singlet ◽  
Direct Photolysis

Photolysis of some alkyl-1-pyrazolines

1968 ◽  
Vol 46 (21) ◽  
pp. 3305-3313 ◽  
Author(s):  
Ralph Moore ◽  
Anupama Mishra ◽  
Robert J. Crawford
Keyword(s):  
Excited Singlet ◽  
Direct Photolysis ◽  
Cis And Trans ◽  
Singlet Methylene

The direct and photosensitized photolysis of six methylated-1-pyrazolines is described. Examination of the products suggests that direct photolysis leads to an excited singlet trimethylene, whereas a triplet is produced on benzophenone photosensitization. The trimethylene produced from 4 and 5 is related to the intermediates produced on addition of triplet methylenes to cis- and trans-2-butene. Evidence is presented to support the claim that no intermediate is involved in the addition of singlet methylene to cis-and trans-2-butene.

The solution-phase photochemistry of 2-trifluoromethylnorbornene

1990 ◽  
Vol 68 (11) ◽  
pp. 1961-1966 ◽  
Author(s):  
N. Nguyen ◽  
B. E. Harris ◽  
K. B. Clark ◽  
W. J. Leigh
Keyword(s):  
Rydberg State ◽  
Singlet State ◽  
High Energy ◽  
Sigmatropic Rearrangement ◽  
Solution Phase ◽  
Excited Singlet ◽  
Direct Photolysis ◽  
Additional Support ◽  
193 Nm ◽  
Π State

The photochemistry of 2-trifluoromethylnorbornene in pentane solution has been investigated. Direct photolysis with 193 nm light yields 1-trifluoromethyl-2-norcarene in 90% yield, due to formal [1,3]-sigmatropic rearrangement, in addition to three other minor products. Chlorobenzene-sensitized photolysis affords photoreduction products, principally exo- and endo-2-trifluoromethylnorbornane and decane isomers, in addition to several products of higher molecular weight. On the basis of comparisons of the photochemistry of this compound to that previously reported for norbornene and 2-cyanonorbornene, as well as spectroscopic evidence, it is suggested that the lowest excited singlet state (the photoreactive state in solution) in 2-trifluoromethylnorbornene is the π, π* state. The results indicate that trifluoromethyl substitution has the effect of significantly raising the energy of the π,R(3s) Rydberg state in simple alkenes, without altering the high energy (ca. 6.5 eV) or the localized character of the alkene π, π* state. Furthermore, they lend additional support to the view that the carbene-derived products typically formed upon photolysis of alkenes in solution are derived from π,R(3s) excitation. Keywords: Rydberg, photolysis, far-uv, alkene, solution phase, singlet, triplet.

The Gold Porphyrin First Excited Singlet State¶

2002 ◽  
Vol 76 (1) ◽  
pp. 47 ◽  
Author(s):  
Joakim Andréasson ◽  
Gerdenis Kodis ◽  
Su Lin ◽  
Ana L. Moore ◽  
Thomas A. Moore ◽  
...  
Keyword(s):  
Singlet State ◽  
Excited Singlet State ◽  
Excited Singlet

scholarly journals UV/Vis-Based Persulphate Activation for p-Nitrophenol Degradation

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 480
Author(s):  
Valentin Dubois ◽  
Carmen S. D. Rodrigues ◽  
Ana S. P. Alves ◽  
Luis M. Madeira
Keyword(s):  
Reaction Time ◽  
Oxidation Process ◽  
Activation Process ◽  
Direct Photolysis ◽  
Simulated Solar Light ◽  
Uv Visible ◽  
Oxidation Efficiency ◽  
Nitrophenol Degradation ◽  
Persulphate Oxidation ◽  
Radiation Type

In the present work, the degradation of p-nitrophenol (PNP) and its mineralization by a UV/Vis-based persulphate activation process was investigated. Firstly, a screening of processes as direct photolysis, persulphate alone and persulphate activated by radiation was performed. The incidence of radiation demonstrated to have an important role in the oxidant activation, allowing to achieve the highest PNP and total organic carbon (TOC) removals. The maximum PNP oxidation (100%) and mineralization (61.6%)—both after 2 h of reaction time—were reached when using T = 70 °C, (S2O82−) = 6.4 g/L and I = 500 W/m2. The influence of radiation type (ultraviolet/visible, visible or simulated solar light) was also evaluated, being found that the source with the highest emission of ultraviolet radiation (UV/visible) allowed to achieve the best oxidation efficiency; however, solar radiation also reached very-good performance. According to quenching experiments, the sulphate radical is key in the activated persulphate oxidation process, but the hydroxyl radical also plays an important role.

Kinetic studies of excited singlet oxygen atom O( 1 D) reactions with ethanol

2021 ◽  
Author(s):  
Hongtao Zhong ◽  
Chao Yan ◽  
Chu C. Teng ◽  
Timothy Y. Chen ◽  
Gerard Wysocki ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Singlet Oxygen ◽  
Kinetic Studies ◽  
Excited Singlet
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