Structure of 1,3,5,7-tetranitroadamantane, C10H12N4O8

Abstract

Mr=316-23, tetragonal, P42IC, a=b= 7.874 (2), c-- 10.552 (2) A, V= 654.2 (2) A a, Z = 2, D x = 1.605 Mg m -a, 2(Cu Kt~) = 1.54178 A, /~ = 1.24 mm -I, F(000) = 328, T= 300 K. Final R = 0.027 for 296 independent observed reflections. The molecule lies on a crystallographic 74 axis coincident with the axis through opposing secondary C atoms in the adaman- tane cage. The nitro groups are rotated approximately 15 ° from a symmetrical eclipsed position with the adjacent cage bonds to the C atoms on the 4 axis. The crystal symmetry is identical to that of the low- temperature form of the unsubstituted adamantane. Introduction. The title compound (TNA) was provided by G. SoUott who first synthesized the material (Sollott & Gilbert, 1980). This compound was investigated as a part of a continuing program to examine the structures of high-density polynitro organic compounds. It is one of a series of nitroadamantanes examined (George & Gilardi, 1983) to provide a library of observed structural parameters for energetic organic substituents. These are used to evaluate and modify semi-empirical parameters used to predict the properties of nitro- organic compounds by methods of quantum chemistry or conformational energy analysis.