Chlorotrinitromethane and its exceptionally short carbon-chlorine bond.

Compounds that deviate from the normal range of bonding can help to assess the strengths and weaknesses of the models currently used to describe chemical bonds. Furthermore, computer simulations of molecules require experimental data to describe accurately the energies and forces between interacting molecules. Compounds that contain the trinitromethyl group, with three nitro groups bonded to one carbon atom, show remarkable inter- and intramolecular effects. In this paper, we report the structural features of chlorotrinitromethane in the solid state and present the first reliable solid-state geometry parameters of an α-halogen derivative of the trinitromethyl pseudohalogen. We found several intriguing geometrical features in terms of intra- and intermolecular interactions, as well as an exceptionally short carbon-chlorine bond (1.694(1) Å). Using a combined crystallographic and computational approach, we show that these effects can be described in terms of the computed electrostatic potential of the molecular surface.