Abstract:

In the structure of the title compd., C₁₂H₈Br₂, the two Br substituents are oriented exo to the boat-shaped cyclooctatetraene at the two ring sites that are β to the ring fusion positions.  The av. Br-C bond distance is 1.919(2) Å, the av. distance for C=C double bonds that are Br substituted is 1.328(2) Å, while the other two double-bond distances are 1.327(2) and 1.398(2) Å for the nonfused and fused bonds, resp.  Each type of ring interat. distance is within s.u. of the av. values for the four known structures, including the title compd., of benzo-fused cycloocatatetraenes that are not coordinated to a metal atom.  The crystal structure features short Br···Br [3.6620(3) Å] and C···H [2.834(2) and 2.841(2) Å] contacts.  Crystallog. data and at. coordinates are given.

Publisher's Version