STRUCTURE OF 1,1,3,3-TETRANITROCYCLOBUTANE

C4H4N4O8, M(r) = 236.1, triclinic, P1BAR, a = 6.301 (1), b = 7.858 (1), c = 8.736 (1) angstrom, alpha = 85.88 (1), beta = 84.62 (1), gamma = 85.13 (1)-degrees, V = 428.2 (1) angstrom3, Z = 2 (two half molecules per asymmetric unit), D(x) = 1.831 Mg m-3, lambda(Cu Kalpha) = 1.54184 angstrom, mu = 1.56 mm-1, F(000) = 240, T = 295 K, final R = 0.031, wR = 0.039 for 575 independent observed reflections. The cyclobutane rings are exactly planar (each one sits on a separate crystallographic inversion center) with the gem-dinitro substituents disposed symmetrically above and below the ring plane. The planes of the two nitro groups bonded to the same C atom are perpendicular to one another (dihedral angles of 89.3 and 88.4-degrees for the two independent molecules).