Formula C7H12ClN5 Density 1.3 g/cm³ | Molar mass 201.657 g/mol Appearance White crystalline powder | |
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Simazine is an herbicide of the triazine class. The compound is used to control broad-leaved weeds and annual grasses.
Contents
Preparation
Simazine may be prepared in the laboratory from cyanuric chloride crystals and a strong solution of ethyl amine (at least 50 percent by number in water). The reaction is highly exothermic and is therefore best carried out in an ice bath below 10 °C. It is also essential to carry out the synthesis in a fume hood since cyanuric chloride decomposes at high temperatures into hydrogen chloride and hydrogen cyanide, both of which are highly toxic by inhalation.
Properties and uses
Simazine is an off-white crystalline compound which is sparingly soluble in water. It is a member of the triazine-derivative herbicides, and was widely used as a residual nonselective herbicide, but is now banned in European Union states. Like atrazine, a related triazine herbicide, it acts by inhibiting photosynthesis. It remains active in the soil for 2-7 months or longer after application.