CAS #: 886-50-0
Categories: Herbicides
Description:
NOMENCLATURE
Common name: terbutryn; terbutryne
IUPAC name: N2-tert-butyl-N4-ethyl-6-methylthio-1,3,5-triazine-2,4-diamine
Chemical Abstracts name: N-(1,1-dimethylethyl)-N'-ethyl-6-(methylthio)-1,3,5-triazine-2,4-
diamine
PHYSICAL CHEMISTRY
Composition: Tech. is 98%.
Mol. wt.: 241.4;
M.f.: C10H19N5S;
Form: White powder.
M.p.: 104-105C.
B.p.: 274C/101 kPa.
V.p.: 0.225 mPa (25C) (OECD 104).
KOW: logP = 3.65 (25 oC, unionised).
Henry: 1.5x10-3 Pa m3 mol-1 (calc.)
S.g./density: 1.12 (20C).
Solubility: In water 22 mg/l (22C). In acetone 220, hexane 9, n-octanol 130, methanol 220, toluene 45 (all in g/l, 20C). Also readily soluble in dioxane, diethyl ether, xylene, chloroform,
carbon tetrachloride, dimethylformamide. Slightly soluble in petroleumether.Stability:
Stable under normal conditions. The methylthio group is hydrolysed in the presence of
strong acids or alkalis. At 70C, no significant hydrolysisCcurs at pH 5, 7, or 9. pKa:
4.3, weak base.
APPLICATIONS
Biochemistry: Photosynthetic electron transport inhibitor at the photosystem II receptor
site.
Mode of action: Selective herbicide, absorbed by the roots and foliage, with translocation
acropetally through the xylem, and accumulation in the apical meristems.
Uses: Used pre-emergence in winter cereals, at 1-2 kg a.i./ha, to control blackgrass and annual meadow grass. Among the autumn-germinating broad-leaved weeds controlled are chickweed, mayweed, poppies and speedwell, but cleavers are rather resistant. Other pre-emergence uses are on sugar cane and sunflowers; and, in mixture with terbuthylazine, on beans, peas and potatoes. In mixture with metolachlor, used in cotton and peanuts. Also used post-emergence (0.2-0.4 kg/ha) in cereals, (1-3 kg/ha) in sugar cane, and as a directed spray in maize. As 'Clarosan', it is used to control algae and submerged vascular plants in waterways, reservoirs and fish ponds.
Phytotoxicity: Not safe for post-emergence use in cereals which are under stress.
Formulation types: FW; GR; MG; SC; WP.
