Photoisomerization kinetics of trifloxystrobin
Kaushik Banerjee1,2, Axel Patrick Ligon1, and Michael Spiteller1
1Institute of Environmental Research (INFU), University of Dortmund, Campus North, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany 2Present address: National Research Centre for Grapes, Pune-412 307, India
Received 27 January 2005
Received 15 April 2005
Accepted 8 May 2005
The photoisomerization kinetics of trifloxystrobin (TFS) in acetone under artificial sunlight is reported. HPLC analysis showed the TFS, a strobilurine fungicide of EE conformation, was converted into an equilibrium mixture of four isomers after illumination for 7 h. The isomers were identified as EZ, EE, ZZ, and ZE and were separated in the crystalline form by preparative HPLC and characterized by use of a variety of spectroscopic techniques. The quantum yield and reaction constants for the isomerization reactions were determined. The detailed spectral features of the individual isomers measured by UV, IR, Raman, NMR and mass spectroscopy are presented and compared. The spectra of the isomers were found to be very characteristic, with good analytical significance.
Keywords: Trifloxystrobin; Isomerization kinetics; HPLC; UV; NMR; Mass spectroscopy