Ametryn

Common name: ametryn; ametryne
IUPAC name: N2-ethyl-N4-isopropyl-6-methylthio-1, 3, 5-triazine-2, 4-diamine
Chemical Abstracts name: N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1, 3, 5-triazine-2, 4-diamine
CAS RN: [834-12-8]

PHYSICAL CHEMISTRY
Composition: 96% pure. Mol. wt.: 227.3; M.f.: C9H17N5S; Form: White powder. M.p.: 86.3-87.0 ºC; B.p.: 337 °C/98.6 kPa; V.p.: 0.365 mPa (25 ºC) (OECD 104). KOW: logP = 2.63 (25 ºC). Henry: 4.1x10-4 Pa m3 mol-1 (calc.) S.g./density: 1.18 (22 ºC). Solubility: In water 200 mg/l (20 ºC). In acetone 610, methanol 510, toluene 470, n-octanol 220, hexane 12 (all in g/l, 25 ºC). Stability: Stable in neutral, weakly acidic, and weakly alkaline media. Hydrolysed by strong acids (pH 1) and alkalis (pH 13) to the herbicidally-inactive 6-hydroxy derivative. Slowly decomposed by u.v. light. pKa: 4.1, weak base.

APPLICATIONS
Biochemistry: Photosynthetic electron transport inhibitor at the photosystem II receptor site.
Mode of action: Selective systemic herbicide, absorbed by the leaves and roots, with translocation acropetally in the xylem, and accumulation in the apical meristems.
Uses: Pre- and post-emergence control of most annual grasses and broad-leaved weeds in pineapples, sugar cane, bananas, citrus fruit, maize, cassava, coffee, tea, sisal, cocoa, oil palms, and on non-crop land. Application rates are in the range 2-4 kg/ha, except when used as a directed spray on maize. Also used as a potato haulm desiccant.
Phytotoxicity: Some sugar cane varieties show temporary chlorosis and scorching of lower leaves.
Formulation types: EC; FW; SC; WG; WP.