Two structures of the trinitromethane anion are reported. In tetra-n-b
utylammonium trinitromethanide, (C4H9)(4)N+. [C(NO2)(3)](-), the [C(NO
2)(3)](-) anion adopts the commonly observed C-2v conformation, while
in the Cs salt, caesium trinitromethanide, Cs+.[C(NO2)(3)](-), it adop
ts a distorted propeller conformation. Both stuctures exhibit cation-a
nion interactions that may influence the structure of the anion.