Direct photolysis of tetrafluoroethylene at 1849 Å

1969 ◽  
Vol 47 (20) ◽  
pp. 3871-3875 ◽  
Author(s):  
J. R. Dacey ◽  
J. G. F. Littler
Keyword(s):  
Double Bond ◽  
Fluorine Atom ◽  
Photochemical Reactions ◽  
Quantum Yields ◽  
Direct Photolysis

The photolysis of C2F4 at 1849 Å gives the following products, whose quantum yields are strongly dependent on substrate pressure: C2F6, C2F2, cyclo-C4F8, cyclo-C3F6, C3F6, C3F8, and polymer.The primary photochemical reactions are tentatively identified, and involve double bond fission and fluorine molecule and fluorine atom elimination.

Kinetics of photochemical reactions with excitation by polychromatic radiation

1985 ◽  
Vol 50 (12) ◽  
pp. 2783-2787 ◽  
Author(s):  
Radim Hrdina ◽  
Igor Čepčiansky ◽  
Jaroslav Poskočil
Keyword(s):  
Experimental Data ◽  
Photochemical Reactions ◽  
Quantum Yields ◽  
Calculation Methods ◽  
Quantitative Studies ◽  
Radiation Sources ◽  
Kinetics Of ◽  
Polychromatic Radiation

For quantitative studies of photochemical reactions with low quantum yields the paper suggests application of polychromatic radiation sources whose overall intensity is by orders higher than that of currently available monochromatic sources. The more complicated and laborious calculation methods suggested for treatment of the experimental data can be solved by usual numerical procedures.

Zur Anwendung von Extinktionsdiagrammen des Stillbens in Perfluormethylcyclohexan./Kinetic Analysis of Photochemical Reactions Using Extinction Diagrams

1972 ◽  
Vol 27 (11) ◽  
pp. 1349-1353 ◽  
Author(s):  
Heinz Mauser ◽  
Hans-Joachim Niemann ◽  
Rainer Kretschmer
Keyword(s):  
Kinetic Analysis ◽  
Rate Constants ◽  
Photochemical Reaction ◽  
Photochemical Reactions ◽  
Quantum Yields ◽  
Method Of Calculation

Extinction diagrams are applied for determining the number of partial reactions. In this paper a method is described for the calculation of the concentration of the reacting substances with the aid of extinction diagrams. The concentration values are more suitable for calculation of the rate constants, and in case of photochemical reactions the partial quantum yields, than the directly measured extinction values. The method of calculation is illustrated using the photochemical reaction of stilbene in a perfluorinated solvent as an example.

Der Einfluß der Bandbreite des Anregungslichtes bei der Bestimmung von Quantenausbeuten photochemischer Reaktionen / The Influence of the Bandwidth of the Exciting Light in Determining the Quantum Yields of Photochemical Reactions

1979 ◽  
Vol 34 (11) ◽  
pp. 1344-1351
Author(s):  
R. Schöneich ◽  
J. Bendig ◽  
D. Kreysig
Keyword(s):  
Quantum Yield ◽  
Radiation Intensity ◽  
Photochemical Reactions ◽  
Wave Number ◽  
Quantum Yields ◽  
Exciting Light ◽  
Considerable Influence ◽  
Interference Filters

Monochromatic excitation is one of the experimental requirements for determining quantum yields of photochemical reactions. It can, however, be strictly satisfied only in certain conditions. The photoisomerization of E,E-1,4-diphenylbutadiene-(1,3) is taken as an example for studying the effect of the bandwidth of the exciting light by using interference filters. The bandwidth is shown to have a considerable influence on the experimentally determined value of the partial quantum yield. Identical results are obtained when making allowance for the wave number dependence on radiation intensity and the absorption of the reactant compounds

Photochemical Reactions of Primary Aromatic Amines with Chloromethanes in Solution. I. Spectrochemical Studies

1989 ◽  
Vol 44 (12) ◽  
pp. 1585-1588 ◽  
Author(s):  
Wojciech Boszczyk ◽  
Tadeusz Latowski
Keyword(s):  
Hydrogen Chloride ◽  
Stability Constants ◽  
Aromatic Amines ◽  
Photochemical Reactions ◽  
Quantum Yields ◽  
Excited Singlet ◽  
Singlet States ◽  
Primary Aromatic Amines ◽  
Excited Singlet States ◽  
Induced Reaction

Interactions were studied of aniline, 4-methoxyaniline and 4-ethoxyaniline with tetrachloromethane, chloroform and dichloromethane in their ground and first excited singlet states. Stability constants of the complexes of these amines with the chloromethanes in cyclohexane were determined as well as their quantum yields of fluorescence in this solvent. The quenching of fluorescence of aniline and its derivatives by the chloromethanes was ascertained and characterized. Quantum yields of the formation of hydrogen chloride, ψΗCl, were measured during photochemically induced reaction of the amines in tetrachloromethane, chloroform and dichloromethane.

Direct Photolysis of 2-Propanol Vapor

1972 ◽  
Vol 50 (14) ◽  
pp. 2217-2223 ◽  
Author(s):  
O. S. Herasymowych ◽  
A. R. Knight
Keyword(s):  
Quantum Yield ◽  
Wavelength Range ◽  
Exposure Time ◽  
Yield Enhancement ◽  
Quantum Yields ◽  
Unimolecular Decomposition ◽  
Direct Photolysis ◽  
Volatile Products ◽  
Temperature And Pressure

The photolysis of 2-propanol vapor in the 1800–2000 Å wavelength range has been investigated. The volatile products of the reaction and their quantum yields at 80 °C and 200 Torr substrate pressure are H2 (0.64), CH3COCH3 (0.34), CH4 (0.39), CH3CHO (0.29), CO (0.15), and C2H6 (0.08). A mechanism is proposed that accounts for the observed rate variations with substrate pressure, exposure time, temperature, and pressure of inert addend. Acetone and acetaldehyde undergo significant secondary decomposition and this is the source of CO, CH4, and C2H6. Acetaldehyde is formed in the unimolecular decomposition of C3H7O radicals produced in the primary process.The effects of CO2 and CF4 as inert addends have been examined and it has been established that the quantum yield enhancement through collision induced predissociation that has been reported to occur in methanol is not a characteristic of the 2-propanol photolysis.

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