THEORETICAL PROPOSAL OF NEW MOLECULES TO REPLACE CHLORDANE

Abstract

Chlordane was a most used as insecticide by farmers. Today, it is banned owing to its toxicity, bio-accumulative and persistence properties. Since then ¶tits prohibition has created more unexploited stocks in the environment. ¶In order to still allow the use of these products, we theoretically proposed new molecules derived from it. To meet this objective, we have reduced the number of chlorine atoms in the chlordane molecule to four. Thus, t¶he QSAR and QSPR models already established made it possible to theoretically determine and the of 70 molecules proposed. ¶The analysis of the results allowed to retain two molecules. These are (1S,2S,3R,6R,7R)-3,8,10,10-tetrachlorotricyclo[5,2,1.02,6]dec-8-ene) and (1R,2R,3R,6R,7S)-3,8,7,8-tetrachloro-tricyclo[5.2.1.02,6]dec-8-ene. Both¶bothbbbbbbbggddaaa molecules seem to present the best values of and BCF.¶¶In order to also verify the influence of fluorine on chlordane, we carried out another study. In this part, we have considered the two abovementioned molecules on which a substitution of four hydrogen atoms by four fluorine atoms was made. This gave the following two molecules: (1R,2S,3S,4R,6R,7S)-3,8,10,10-tetrachloro-1,4,7,9-tetrafluorotricyclo[5,2,1,02,6]dec-8-ene and (1S,2S,3R,4S,6S,7S)-1,3,7,8-tetrachloro-4,9,10,10-tetrafluorotricyclo[5,2,1,02,6]dec-8-ene. Both ¶both molecules show higher BCF values ​​than the formers. This would mean that organochlorine compounds which have fluorine atoms are storable. Besides, when we consider the fact that these molecules are more absorbent, (1R,2S,3S,4R,6R,7S)-3,8,10,10-tetrachloro-1,4,7,9-tetrafluorotricyclo[5,2,1,02,6]dec-8-ene and (1S,2S,3R,4S,6S,7S)-1,3,7,8-tetrachloro-4,9,10,10-tetrafluorotricyclo[5,2,1,02,6]dec-8-ene appear to be less accumulable and less toxic than (1S,2S,3R,6R,7R)-3,8,10,10-tetrachlorotricyclo[5,2,1.02,6]dec-8-eneand (1R,2R,3R,6R,7S)-3,8,7,8-tetrachloro-tricyclo[5.2.1.02,6]dec-8-ene.