Zum Photoabbau von l-(4-Chlorphenyl)-4,4-dimethyl-3-(1H-1,2,4-triazoll- ylmethyl)-pentan-3-ol (Folicur®) [1] / On the Photodegration of l-(4-Chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-l-ylmethyl)-pentan-3-ol (Folicur®) [1

Abstract

The photodegradation of the 1,2,4-triazole fungicide Folicur 1 in different organic solvents (benzene, ether, methylene chloride, methanol) and water, in absence and in presence of a singlet oxygen sensitizer (methylene blue) has been studied. The photometabolites formed in organic solvents, have been separated by column chromatography (with isolation of 4 -7 , 13 and 14) and in the case of benzene as solvent as well with the aid of HPLC (isolated: 4 -7 , and five additional products 8-12). Photodegradation of 1 in water leads to the formation of only two photoproducts: 4 and 17 (separated only by HPLC). Identification has been achieved by spectroscopic methods and comparison (of retention times, UV and mass spectra) with authentic samples. Furthermore, the kinetics of the photodegradation of 1 in benzene and water (also after addition of titanium dioxide) has been established by HPLC-UV/VIS-technique. The interpretation of the kinetics allows conclusions towards the photodegradationmechanism, which is discussed in the paper. As expected, the addition of the photocatalyst titanium dioxide leads to a significant acceleration of the photodegradation.