2,11-Dibromo-5,8-dibut-yl[4]helicene

Acta Crystallogr Sect E Struct Rep Online. 2012 Apr 1;68(Pt 4):o1239. doi: 10.1107/S1600536812013141. Epub 2012 Mar 31.

Abstract

A racemic mixture of the title compound, C(26)H(26)Br(2), a brominated [4]helicene, crystallizes, forming columns of stacked mol-ecules. There are two crystallographically unique mol-ecules in the asymmetric unit, both with the same helical handedness. As is typical with helicene congeners, the unique mol-ecules show short inter-atomic contacts between H atoms at the fjord region, with H⋯H distances of 1.87 and 1.94 Å. Mol-ecules with the same helical handedness segregate in the crystal packing, forming homochiral columns. The stacked mol-ecules are piled in a column with alternate orientations. The shortest C⋯C distance in the stacked mol-ecules is 3.306 (4) Å.