Isolation of hydrazine oxidation products via halogen bonding: C–I bond scission and crystal polymorphism

Reaction of methylhydrazine with 1,3- and 1,4-diiodotetrafluorobenzene produced cocrystals with the oxidation product sym -hexahydro-1,4-dimethyltetrazine. In contrast, reaction of 1,1-dimethylhydrazine with 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene, as well as 1,3,5-triiodotrifluorobenzene, yielded cocrystals with tetramethylammonium iodide ( NMe 4 I ), via C–I bond scission. For each of the NMe 4 I cocrystals, different polymoprhs or cocrystal stoichiometries were obtained via the C–I bond scission route, than were obtained by direct reaction of the halobenzene and NMe 4 I by standard solution techniques.