Tetrazine

File:1,2,3,4-Tetrazine-2D-numbering.svg

Structure of 1,2,3,4-tetrazine

File:1,2,4,5-tetrazine numbering.png

Structure of 1,2,4,5-tetrazine

Tetrazine is a compound that consists of a six-membered aromatic ring containing four nitrogen atoms with the molecular formula C₂H₂N₄. The name tetrazine is used in the nomenclature of derivatives of this compound. Three core-ring isomers exist: 1,2,3,4-tetrazines, 1,2,3,5-tetrazines, and 1,2,4,5-tetrazines, also known as v-tetrazines, as-tetrazines and s-tetrazines respectively.<ref>Template:Cite book</ref>

1,2,3,4-Tetrazines

1,2,3,4-Tetrazines are often isolated fused to an aromatic ring system and are stabilized as the dioxide derivatives.

1,2,4,5-Tetrazines

1,2,4,5-Tetrazines are very well known and myriad 3,6-disubstituted 1,2,4,5-tetrazines are known.<ref>(see United States Patent 6645325)</ref> These materials are of useTemplate:Vague in the area of energetic chemistry.Template:Cn

Heavily substituted tetrazines form the verdazyls, a family of stable radicals.<ref name=Radicals>Template:Cite book</ref>

Protected tetrazines are strong acetylene acceptors in Diels-Alder equilibria. For example, dipyridinyl 1,2,4,5-tetrazine abstracts acetylene from norbornadiene to cyclopentadiene and a pyridazine:<ref>Template:Multiref</ref>

reaction of norbornadiene with 3,6-di-2-pyridyl-1,2,4,5-tetrazine

With norbornadiene fused to an arene the reaction stops at an intermediary stage.<ref>π-Bond Screening in Benzonorbornadienes: The Role of 7-Substituents in Governing the Facial Selectivity for the Diels-Alder Reaction of Benzonorbornadienes with 3,6-Di(2-pyridyl)-s-Tetrazine. Ronald N. Warrener and Peter A. Harrison Molecules 2001, 6, 353–369 Online Article</ref>

See also

• 6-membered rings with one nitrogen atom: pyridine
• 6-membered rings with two nitrogen atoms: diazines
• 6-membered rings with three nitrogen atoms: triazines
• 6-membered rings with five nitrogen atoms: pentazine
• 6-membered rings with six nitrogen atoms: hexazine