Bipyridilium pesticides

BIPYRIDILIUM PESTICIDES, FLAMMABLE LIQUID, n.o.s., flash point 3015 ... 

Bipyridilium pesticides, liquid, flammable, toxic, n.o.s., flashpoint less than 23 °C. 2782... 

Bipyridilium pesticides, those including or based on bipyridinium such as diquat or paraquat, both herbicides. 

Bipyridilium Pesticides, liquid, toxic. 3015 28 Bromoacelyl Bromide 2513 60... 

As shown by the structures in Figure 15.9, a bipyridilium compound contains two pyridine rings per molecule. The two important pesticidal compounds of this type are the herbicides diquat and paraquat other members of this class of herbicides include chlormequat, morfamquat, and difenzoquat. Applied directly to plant tissue, these compounds rapidly destroy plant cells and give the plant a frostbitten appearance. However, they bind tenaciously to soil, especially the clay mineral fraction, which results in rapid loss of herbicidal activity so that sprayed fields can be planted within a day or two of herbicide application. 

Indeed, the promise of IA has led to workable enzyme-linked immunosorbent assays (ELISAs) for a variety of pesticides, including thiolcarbamates, triazoles and triazines, substituted ureas and sulfonylureas, bipyridilium compounds, and other groups of chemicals(2) (Table I). Additionally, radioimmunoassay (RIA) methods exist for chlorinated hydrocarbons, organophosphates, phenoxy adds and other chemical classes. 

Although the adsorption of this class of organics on soils and soil minerals has been studied in some detail, there are actually few examples of organic cations that are used as pesticides or occur as pollutants in soils. The best known examples are the two bipyridilium quaternary salts, diquat and paraquat, herbicides that are very soluble in water because of their ionic nature. The structure of the chloride salt of paraquat is diagrammed below ... 

Based on scientific data, pesticides that exhibit human and environmental hazards can be forbidden in the USSR, although they may be reconunended by agricultural groups or widely used in other countries. Banned organophosphate pesticides are thimet, azinphos-methyl, dialiphos, dicrotophos, isofenphos, Ultracide and Nemacur organochlorines, aldrin, dieldrin, endrin and isodrin carbamates, Temik and dioxicarb dithiocarbamates, ziram and maneb and bipyridiliums, paraquat (selective pulmotropic action). 

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