Structure of 1,3-dinitronaphthalene.

C10H6N2O4, Mr = 218.2, triclinic, P1, a = 7.5552 (8), b = 7.763 (1), c = 9.073 (1) A, alpha = 110.742 (9), beta = 99.570 (9), gamma = 100.309 (9) degrees, V = 474.1 (2) A3, D chi = 1.528 g cm-3, Z = 2, Cu K alpha (lambda = 1.54178 A, graphite monochromator) mu = 10.5 cm-1, F(000) = 224, T = 293 K, final R = 0.064, wR = 0.092 for 1213 reflections with I greater than 3 sigma (I). The naphthalene ring is planar with an average deviation of 0.004 A from the ten-atom least-squares plane. The C-C distances show the typical naphthalene alternation: C1-C2, C3-C4, C5-C6 and C7-C8 average 1.359 A; C2-C3 and C6-C7 average 1.391 A. The C1 nitro group is twisted out of the ring plane by approximately 37 degrees to relieve non-bonded interactions between an oxygen and the C8-H8 region.