STRUCTURE OF 2-AMINO-4,5-DICYANOIMIDAZOLE

2-Aminoimidazole-4,5-dicarbonitrile, C5H3N5, M(r) = 133.14, monoclinic, C2/m, a = 11.764 (4), b = 9.855 (10), c = 11.656 (4) angstrom, beta = 116.54 (3)-degrees, V = 1209 (1) angstrom 3, Z = 8, D(m) = 1.41 (2), D(x) = 1.46 g cm-3, Mo K-alpha, lambda = 0.7107 angstrom, mu = 0.66 cm-1, F(000) = 544, T = 183 K, R(F) = 0.064 for 1425 independent reflections. There are two independent half molecules in the asymmetric unit, each of which lies perpendicular to a mirror plane. Each molecule forms six hydrogen bonds with neighboring molecules which may explain the unusually high decomposition temperature of 543 K. The molecules form hydrogen-bonded zigzag sheets about the (2BAR02) planes.