Terbuthylazine is a selective herbicide. Chemically, it is a halogenated triazine; compared with atrazine (1958 inv., Geigy lab) and simazine, it has a tert-butyl group \s[C\s(CH3)3] in place of the isopropyl \s[CH\s(CH3)2] and ethyl group, respectively.
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.