Agrochemical Pesticide Herbicide Terbutryn 98%TC 80%WP 50%WP 50%SC CAS:886-50-0

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.

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.