Structure Of Exo,Exo-9,10,12-Tribromotricyclo[6.3.1.02,7]Dodeca-2(7),3,5,10-Tetraene

Abstract

C12H9Br3, M(r) = 392.915, orthorhombic, P2(1)2(1)2(1), a = 6.979 (4), b = 9.596 (1), c = 18.056 (4) angstrom, V = 1209.22 angstrom 3, Z = 4, D(m) = 2.1, D(x) = 2.158 g cm-3, lambda(Cu K-alpha) = 1.54180 angstrom, mu(Cu K-alpha) = 122.24 cm-1, F(000) = 744, T = 293 K, R = 0.044 for 1254 observed reflections. In the title compound, the Br(1)-C(12) [1.966 (9) angstrom] and Br(3)-C(9) [1.971 (7) angstrom] distances are almost equal but Br(2)-C(10) [1.892 (7) angstrom] is shorter. The structural analysis has revealed that the starting compound, 9-bromotricyclo[6.2.2.0(2,7)]dodeca-2(7),3,5,9,11-pentaene, a [2.2.2] system, has rearranged to the title compound, a [3.2.1] system, via an aryl shift.