An X-ray study of some 2,3-diphenyltetrazolium salts

An X-ray diffraction study is reported for three molecules of salts containing a cation with a positive charged 2,3-diphenyltetrazolium ring. The results confirm aromatic structure of the tetrazole ring and the delocalization of charge on the whole molecules of the cations. The molecular geometry obtained is compared with that for free mesoionic 2,3-diphenyltetrazoles which have already been studied and the ring parameters do not reveal significant differences. But is shows that the geometry of the (NNO)^– exocyclic group is changed as a result of alkylation. Compound I C₁₃H₁₂N₅Cl, P2₁/a,a=16.934(4),b=6.575(1),c=26.121(4) Å, =108.15(2)°, II C₁₄H₁₃N₆OI, P3₁2,a=10.774(3),c=12.821(4) Å, IV C₂₆H₂₀N₈Cl₂, C2/c,a=22.316(4),b=6.6903(7),c=20.437(3) Å, =92.51(1)°.