Reaction of 2,4,6-triazido-1,3,5-triazine with triphenylphosphane. syntheses and characterization of the novel 2-triphenylphosphanimino-4-azidotetrazolo[5,1-a]-[1,3,5]triazine and 2,4,6,-tris(triphenylphosphanimino)-1,3,5-triazine.
2-Triphenylphosphanimino-4-azidotetrazolo[5,1-a]-[1,3,5]triazine (6) was obtained by reaction of 2,4,6-triazido-1,3,5-triazine (1) with 1 equiv of triphenylphosphane. Raman and X-ray data revealed that only one azide group formed a tetrazole ring system whereas the second azide group did not undergo ring closure. To investigate the equilibrium between the tetrazole isomer and the open-chain azide structure for these and related species, (31)P NMR studies were carried out. The obtained spectra displayed an equilibrium between the tetrazole and the open-chain azide isomers. 2,4,6-Tris(triphenylphosphanimino)-1,3,5-triazine (4) was prepared by treatment of 1 with 3 equiv of triphenylphosphane, and its X-ray structure is discussed. On the basis of PM3 semiempirical and density functional calculations, the reaction of 1 with triphenylphosphane was studied. The thermodynamics of different isomerization reactions and the activation barriers to cyclization were estimated.
Kessenich
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E
Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus D), D-81377 München, Germany.
Polborn
K
K
Schulz
A
A