Intra- and intermolecular electrostatic interactions and their significance for the structure, acidity, and tautomerization behavior of trinitromethane

We have addressed several interesting issues related to trinitromethane: the propellerlike arrangement of its nitro groups, its lower-than-predicted (although still high) acidity, its aci tautomerization, and the absence of expected very short C - H * * * O intermolecular bridges in the crystal. A combination of crystallographic and computed data was used in our analysis. The structural features mentioned and the anomalous acidity can be attributed to intra- and/or intermolecular electrostatic interactions. Decomposition via C - NO 2 bond scission may occur before aci tautomerization can take place.