Kinetic studies on the enantiomerization and racemization of a pesticide triadimefon

Author: Saba Jorbenadze
Keywords: Racemization, Enantiomerization, Kinetic
Annotation:

Triadimefon is a fungicide used in agriculture to control various fungal diseases. As a seed treatment, it is used on wheat, corn, cotton, etc. In fruit it is used on various citruses, banana and pineapple. Non-food uses include pine seedlings, Christmas trees, ornamental plants. For chiral pesticides using instead of racemates only their biologically active enantiomer may enable reducing their applied amount twice and thus significantly reduce the unwanted side effects on target and nontarget species and the environment. However, single enantiomers may undergo racemization in the species or medium they are applied in and thus their activity will get significantly reduced. Based on the abovementioned, kinetic studies of enantiomerization and racemization of chiral pesticides belong to the hot topics of contemporary chemistry. The goal of the present study was to investigate an enantiomerization and racemization of triadimefon using dynamic chromatography and the methods of classical chemical kinetics, accordingly. Since the dynamic chromatographic experiment is performed on a chromatographic column in the specified mobile phases it is possible that chromatographic packing material acts as a heterogeneous catalyst and some components of a mobile phase as a homogeneous catalyst of the enantiomerization process. No attention was paid to this issue in the scientific literature until now. Therefore, in the present study the process of enantiomerization of triadimefon was studied in chiral chromatographic columns which were packed with different chiral stationary phases. In addition, the possible catalytic role of diethylamine, that is used as the additive to the mobile phase in order to improve peak shape, was evaluated.