Atrazine

Common name: atrazine
IUPAC name: 6-chloro-N2-ethyl-N4-isopropyl-1, 3, 5-triazine-2, 4-diamine
Chemical Abstracts name: 6-chloro-N-ethyl-N'-(1-methylethyl)-1, 3, 5-triazine-2, 4-diamine
CAS RN: [1912-24-9]

PHYSICAL CHEMISTRY
Composition: Tech. is 97% pure. Mol. wt.: 215.7; M.f.: C8H14ClN5; Form: Colourless powder. M.p.: 175.8 ºC; B.p.: 205.0 °C/101 kPa; V.p.: 3.85x10-2 mPa (25 ºC) (OECD 104). KOW: logP = 2.5 (25 ºC). Henry: 1.5x10-4 Pa m3 mol-1 (calc.) S.g./density: 1.23 (22 °C) Solubility: In water 33 mg/l (pH 7, 22 ºC). In ethyl acetate 24, acetone 31, dichloromethane 28, ethanol 15, toluene 4.0, n-hexane 0.11, n-octanol 8.7 (all in g/l, 25 ºC). Stability: Relatively stable in neutral, weakly acidic and weakly alkaline media. Rapidly hydrolysed to the hydroxy derivative in strong acids and alkalis, and at 70 ºC in neutral media; DT50 (pH 1) 9.5, (pH 5) 86, (pH 13) 5.0 d. pKa: 1.7, v. weak base.

APPLICATIONS
Biochemistry: Photosynthetic electron transport inhibitor at the photosystem II receptor site. Maize tolerance is attributed to rapid detoxification by glutathione transferases.
Mode of action: Selective systemic herbicide, absorbed principally through the roots, but also through the foliage, with translocation acropetally in the xylem and accumulation in the apical meristems and leaves.
Uses: Pre- and post-emergence control of annual broad-leaved weeds and annual grasses in maize, sorghum, sugar cane, pineapples, chemical fallow, grassland, macadamia nuts, conifers, industrial weed control. In Europe, use is concentrated in maize and sorghum. Used also in combinations with many other herbicides.
Phytotoxicity: Phytotoxic to many crops, including most vegetables, potatoes, soya beans, and peanuts.
Formulation types: FW; GR; SC; WG; WP.