Derivatives of s-tetrazine containing malonodinitrile, ethyl cyanoacetate, and 1,3-indanedione fragments were synthesized by the nucleophilic substitution of heterocyclic groups in 3,6-diazolyl-1,2,4,5-tetrazines. Coordination compounds of the cyanomethyltetrazine anion with Cu+, Mn2+, and the tetrathiafulvalene radical cation were obtained, and their structures were determined. A transformation of cyanomethyltetrazines to pyrrolo[1,2-b][1, 2, 4, 5]tetrazines catalyzed by metal cations was discovered