Optimization of Molecular Models for Calculating Quantum Yields of Photochemical Reactions

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.

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

Zeitschrift für Naturforschung B ◽

10.1515/znb-1972-1113 ◽

1972 ◽

Vol 27 (11) ◽

pp. 1349-1353 ◽

Cited By ~ 15

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.

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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

Zeitschrift für Naturforschung A ◽

10.1515/zna-1979-1114 ◽

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

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

Zeitschrift für Naturforschung B ◽

10.1515/znb-1989-1220 ◽

1989 ◽

Vol 44 (12) ◽

pp. 1585-1588 ◽

Cited By ~ 4

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.

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Thermally irreversible photochromic dithienylethenes

International Journal of Photoenergy ◽

10.1155/s1110662x9900032x ◽

1999 ◽

Vol 1 (3) ◽

pp. 183-190 ◽

Cited By ~ 7

Author(s):

M. M. Krayushkin ◽

B. M. Uzhinov ◽

A. Yu. Martynkin ◽

D. L. Dzhavadov ◽

M. A. Kalik ◽

...

Keyword(s):

Photochemical Reactions ◽

Quantum Yields ◽

Spectral Parameters ◽

Derivatives Of

A lot of previously unknown derivatives of dithienylperfluorocyclopentene (DTPFCP) were synthesized. It was shown that2,2′-dialkylsubstituted DTPFCP'S are phtochromes. The quantum yields of forward and backward photochemical reactions and spectral parameters of open and cyclic forms of the photochromes synthesized were measured. An attempt to obtain fluorescing phtochromes by means of introduction of benzoxazolyl, benzthiazolyl and 1,2,4-oxadiazolyl moieties in 5 and5′positions of DTPFCP failed; these compounds were synthesized but they do not fluoresce.

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