2',2'-TETRACHLORO-1,1'-DIPHENYL-1,1'-BICYCLOPROPYL AND ,2',2'-TETRABROMO-1,1'-DIPHENYL-1,1'-BICYCLOPROPYL

Molecules of meso-2,2,2',2'-tetrachloro-1,1'-diphenyl- 1,1'-bicyclopro pyl, C18H14Cl4, (1), and 2',2'-tetrabromo-1,1'-diphenyl-1,1'-bicyclopr opyl, C18H14Br4, (2), adopt gauche conformations, Compound (1) produce d two types of crystals upon recrystallization, The phenyl rings of th e two forms of compound (1), as well as those of compound (2), are in a nearly perpendicular orientation, All three structures have unsymmet rical cyclopropane rings, with the shortest C-C bond being between the rings at the point of phenyl substitution.