Pentaerythritol crystal structure

Crystal Structure of the Tetraacetate and Tetra-nitrate of Pentaerythritol , ZKrist 66, 355—92... 

Working first with Polanyi, Weissenberg, and Brill, and later as the leader of the Textile Chemistry Section, Mark successively published papers on the crystal structures of hexamethylenetetramine, pentaerythritol, zinc salts, tin, urea, tin salts, triphenylmethane, bismuth, graphite, sulfur, oxalic acid, acetaldehyde, ammonia, ethane, diborane, carbon dioxide, and some aluminum silicates. Each paper showed his and the laboratory s increasing sophistication in the technique of X-ray diffraction. Their work over the period broadened to include contributions to the theories of atomic and molecular structure and X-ray scattering theory. A number of his papers were particularly notable including his work with Polanyi on the structure of white tin ( 3, 4 ), E. Wigner on the structure of rhombic sulfur (5), and E. Pohland on the low temperature crystal structure of ammonia and carbon dioxide (6, 7). The Mark-Szilard effect, a classical component of X-ray physics, was a result of his collaboration with Leo Szilard (8). And his work with E. A. Hauser (9, 10, 11) on rubber and J. R. 

Erythritol tetranitrate (ETN) (Figure 1) is an explosive first prepared in 1849 [1] with similar properties to pentaerythritol tetranitrate (PETN). ETN is melt-castable, has impressive performance, and is not difficult to prepare, which increases the necessity for understanding its properties from a homemade explosive threat determination perspective [2]. Due to its handling sensitivity, ETN has been involved in recent accidents [3] and should not be handled outside of a dedicated explosives facility. We have recently reported the first X-ray crystal structure of ETN [4], and discussed the influence of crystal packing on the sensitivity of the material, relative to PETN [5]. Another recent publication also discusses basic characterization of ETN [6]. 

Covalent nitrates. Apart from organic nitrates covalent nitrates of non-metals are limited to those of H, F, and Cl. (CINO3 has been prepared from anhydrous HNO3 and CIF as a liquid stable at —40°C in glass or stainless steel vessels. 9 Electron diffraction studies have been made of the explosive gas FN03 and of the (planar) methyl nitrate molecule. A refinement of the crystal structure of pentaerythritol nitrate, C(CH20N02)4, shows that the nitrate group has the same structure, (d), as in nitric acid. 

Molecules of this form are linked in the crystal by hydrogen bonds of length approximately 2 95 A to form two-dimensional sheets (fig. 14.07 b), and the three-dimensional structure is built up by a superposition of these sheets. As in pentaerythritol, the crystals are very stable (they decomposite at 420 °C without melting) and possess a perfect cleavage parallel to the sheets. 

---