1,1-Diamino-2,2-dinitroethylene: a Novel Energetic Material with Infinite Layers in Two Dimensions

The title compound (C₂H₄N₄O₄) is a novel and interesting high explosive with high performance and low sensitivity. Single-crystal X-ray diffraction studies of the compound show that the molecules in the crystal structure have bond lengths and bond angles as expected for this type of push-pull ethylene. There are two intramolecular hydrogen bonds present between the nitro-O atoms and the amino-H atoms. The geometry of the molecule indicates that there is extensive [pi] conjugation present. The molecular packing is built up by infinite two-dimensional wave-shaped layers, with extensive intermolecular hydrogen bonding within the layers and ordinary van der Waals interactions between the layers. The crystal packing explains some of the physico-chemical properties of the compound such as the absence of a melting point, its low solubility and its low sensitivity to friction and impact compared with the common high explosive RDX (1,3,5-triaza-1,3,5-trinitrocyclohexane).

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