Triazines
A triazine is class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C3H3N3. They exist in three isomeric forms, 1,3,5-triazines being common.
The triazines have planar six-membered benzene-like ring but with three carbons replaced by nitrogens. The three isomers of triazine are distinguished by the positions of their nitrogen atoms, and are referred to as 1,2,3-triazine, 1,2,4-triazine, and 1,3,5-triazine. Other aromatic nitrogen heterocycles are pyridines with one ring nitrogen atom, diazines with 2 nitrogen atoms in the ring and tetrazines with 4 ring nitrogen atoms.
The best known triazines are derivatives of the 1,3,5-triazine derivatives melamine and cyanuric chloride (2,4,6-trichloro-1,3,5-triazine). With three amino substituents melamine is a precursor to commercial resins. Another triazine extensively used in resins is benzoguanamine. Chlorine-substituted triazines are components of reactive dyes. These compounds react through a chlorine group with hydroxyl groups present in cellulose fibres in nucleophilic substitution, the other triazine positions contain chromophores. Triazine compounds are often used as the basis for various herbicides.
Triazines also have wide use in the oil and gas and petroleum processing industries as a non-regenerating sulfide removal agent; they are applied to fluid streams to remove hydrogen sulfide gas and mercaptan species, which can decrease the quality of the processed hydrocarbon and be harmful to pipeline and facility infrastructure if not removed.
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