ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Photooxidation of Arylazo-Naphtholes with Singlet OxygenThe reaction of p-substituted 4-arylazo-1-naphtholes 1 and 1-arylazo-2-naptholes 5 with singlet oxygen (produced by methylene blue-sensitized photolysis) has been studied spectroscopically in methanol as a solvent. The rate constants of dye bleaching are the same, irrespective whether the extinctions of the azo or the hydrazone forms of the tautomeric systems are measured. Both reaction series 1 and 5 afford linear Hammett plots, which is discussed in the light of the azohydrazone equilibrium of the dyes and an „ene“ mechanism of the reaction with singlet oxygen. It could be shown by short-time spectroscopy that the azo-hydrazone isomerization proceeds much faster than the attack of singlet oxygen on the hydrazone form, which explains all observed facts.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19813230614
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