Photochemistry of azo compounds. II. Effect of ketonic sensitizers on photoreduction of 4-diethylamino-4′-nitroazobenzene

✍ Scribed by J.G. Pacifici; Gether Irick Jr.

• Book ID: 104239449
• Publisher: Elsevier Science
• Year: 1969
• Tongue: French
• Weight: 203 KB
• Volume: 10
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)88123-5

✦ Synopsis

In an earlier paper (1) it was shown that the photoreduation of 4-diethylamino-4'-nitroazobenzene (I) in alcoholic media occurred, with low quantum efficienoy, to produce hydrazo compound II, Benzene and naphthalene were inefficient sensitizers of this reaction. We report here the effect of ketonic sensitizers and the mechanism of sensitization.

Quantum yields for hydrogen abstraction by I were low, both in the absence of sensitizers and in the presence of hydrocarbon sensitizers. However, acetone and benzophenone efficiently sensitized the photoreduction of I in the presence of hydrogen donors (benzhydrol or ieopropanol). Fluoren-g-one did not significantly increase the quantum yield for the photoreduction of I. The absence of a dark reaction following partial photodegradation under degassed conditions in the presence of either hydrocarbon or ketonic sensitizers showed that photoisomerization was not important. The results of these experiments are given in Table I.