The Thermal Reaction Between Hydrogen and Oxygen IV. Comparison of the Thermal and the Photochemical Reaction

1941 ◽  
Vol 9 (8) ◽  
pp. 573-578 ◽  
Author(s):  
O. Oldenberg ◽  
H. S. Sommers
Keyword(s):  
Photochemical Reaction ◽  
Thermal Reaction

REACTION OF DIHYDROPYRAN WITH ETHYL AZIDOFORMATE

1965 ◽  
Vol 43 (5) ◽  
pp. 1266-1271 ◽  
Author(s):  
I. Brown ◽  
O. E. Edwards
Keyword(s):  
Good Yield ◽  
Photochemical Reaction ◽  
Thermal Reaction

Photochemical reaction of ethyl azidoformate with dihydropyran gave a good yield of the very reactive aziridine III. The thermal reaction between the two compounds took a completely different course, via triazoline XI to 2-hydroxy-2-ethoxycarbonamidotetrahydropyran XIII.

scholarly journals PHOTOCHEMICAL REACTION OF POLYACRYLONITRILE COMPARED WITH THE THERMAL REACTION

1983 ◽  
Vol 39 (10) ◽  
pp. T415-T420
Author(s):  
Ritsuko Nakamura ◽  
Hiroshisa Yoshida ◽  
Mitsuhiko Hida
Keyword(s):  
Photochemical Reaction ◽  
Thermal Reaction

THE FLASH PHOTOLYSIS OF DIACETYLENE

1957 ◽  
Vol 35 (2) ◽  
pp. 129-133 ◽  
Author(s):  
J. H. Callomon ◽  
D. A. Ramsay
Keyword(s):  
Photochemical Reaction ◽  
Flash Photolysis ◽  
Rotational Temperature ◽  
Thermal Reaction ◽  
Time Interval ◽  
Transient Species ◽  
Flash Tube ◽  
Photolysis Apparatus ◽  
Considerable Excess ◽  
Photochemical Decomposition

A brief description is given of a "microsecond" flash photolysis apparatus in which a 40 µf. condenser charged to 8000 v. is discharged through a photolysis flash tube in ~20 microseconds. Absorption spectra of transient species are photographed with a second flash tube which provides a source of continuum by discharging a 2 µf. condenser charged to 10,000 v., in 3–5 microseconds. A circuit for controlling the time interval between the two flashes is given.Experiments on the flash photolysis of diacetylene are discussed. With diacetylene at 0.5 mm. Hg pressure several well-known band systems were photographed in absorption 20 microseconds after the beginning of the photolysis flash, viz., the C2 Swan bands, the C2 Phillips bands, the C2 Deslandres–d'Azambuja bands, the 4050 Å bands of C3, and the CH band at 3143 Å. The rotational temperature of these bands was ~3000°–5000° K. The C2 Swan bands were also recorded in emission after a single photolysis flash. When a considerable excess (100:1) of helium was added to the diacetylene, all the above band systems disappeared with the exception of the C3 bands.In the absence of helium it is probable that the reaction is mainly thermal and that the high temperature is produced by a thermal explosion of the diacetylene triggered by the photolysis flash. The thermal reaction is suppressed by the addition of excess helium and the photochemical reaction becomes dominant. Under these conditions it is interesting to note that C3, but no C2, is produced. It appears therefore that C3 is a product of the photochemical decomposition of diacetylene. Possible mechanisms are discussed.

Experimental and theoretical study of the photochemical and thermal decomposition of maleic and dichloromaleic anhydrides

2002 ◽  
Vol 80 (5) ◽  
pp. 455-461 ◽  
Author(s):  
A Ionescu ◽  
N Piétri ◽  
M Hillebrand ◽  
M Monnier ◽  
J P Aycard
Keyword(s):  
Thermal Decomposition ◽  
Ir Spectroscopy ◽  
Photochemical Reaction ◽  
Theoretical Study ◽  
Thermal Reaction ◽  
Mo Calculations ◽  
Reaction Conditions ◽  
Decomposition Processes ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The photochemical and thermal behavior of maleic anhydride 1a and dichloromaleic anhydride 1b, in cryogenic matrix were investigated by means of FT-IR spectroscopy. The ketenylcarbenes represent the key intermediate in the decomposition processes of the anhydrides, even if they were not observed experimentally. The yields of the different products depend on the thermal or photochemical reaction conditions. The main photochemical products obtained from 1a were cyclopropenone and acetylene, whereas the major products from 1b were dichlorocyclopropenone and dichloroacetylene, along with small quantities of dichloropropadienone. The thermal reaction leads to dichloro propa dienone, CO, and CO2. MO calculations performed at the HF/6-31G*//HF/6-31G* level support the experimental mechanisms.Key words: photolysis, thermolysis, ab initio calculations, cryogenic matrix, ketenylcarbenes.

Photocatalytic Discolouration of Solutions of Reactive Dyes in the Presence of H2O2

1995 ◽  
Vol 30 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Deng Nansheng ◽  
Tian Shizhong ◽  
Xia Mei
Keyword(s):  
Photochemical Reaction ◽  
Uv Light ◽  
Reactive Dyes ◽  
Solar Light ◽  
Rate Equations ◽  
Oh Radical ◽  
Test Results ◽  
Dye Molecules ◽  
First Order ◽  
Dye Solutions

Abstract Tests for the photocatalytic degradation of solutions of three reactive dyes, Red M-5B, Procion Blue MX-R and Procion Black H-N, in the presence of H2O2 were carried out. When the solutions of the three reactive dyes were irradiated by UV or solar light, the colour of the solutions disappeared gradually. A statistical analysis of the test results indicated a linear relation between the concentration of dyes and the time of irradiation. The discolouration reaction of the solutions was of the first order. Rate equations for the discolouration reactions of dye solutions were developed. The dark reactions or the dye solutions containing H2O2 were very slow, illustrating that the photochemical reaction played a very important role. It was demonstrated that UV light and solar light (300 to 380 nm) photolyzes the HO and that the resulting OH radical reacts with the dye molecules and destroys the chromophore.

Role of Exosomes in Photodynamic Anticancer Therapy

2020 ◽  
Vol 27 (40) ◽  
pp. 6815-6824 ◽  
Author(s):  
Yuan Jiang ◽  
Chuanshan Xu ◽  
Wingnang Leung ◽  
Mei Lin ◽  
Xiaowen Cai ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Basic Principle ◽  
Photochemical Reaction ◽  
Cell Communication ◽  
Anticancer Therapy ◽  
Bioactive Molecules ◽  
Promising Alternative ◽  
Tumor Tissues ◽  
Significant Attention

Photodynamic Therapy (PDT) is a promising alternative treatment for malignancies based on photochemical reaction induced by Photosensitizers (PS) under light irradiation. Recent studies show that PDT caused the abundant release of exosomes from tumor tissues. It is well-known that exosomes as carriers play an important role in cell-cell communication through transporting many kinds of bioactive molecules (e.g. lipids, proteins, mRNA, miRNA and lncRNA). Therefore, to explore the role of exosomes in photodynamic anticancer therapy has been attracting significant attention. In the present paper, we will briefly introduce the basic principle of PDT and exosomes, and focus on discussing the role of exosomes in photodynamic anticancer therapy, to further enrich and boost the development of PDT.

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