Crystal structure of bis(cholesteryl)4,4'-(1,2-phenylenebis(oxy))-dibutanoate: an oligomesogen

The crystal structure of bis(cholesteryl)4,4'-(1,2-phenylenebis(oxy))dibutanoate (C68H106O6) has been determined by direct methods using single-crystal X-ray diffraction data. It crystallises in the monoclinic system with space group P21 and Z = 2. The unit cell parameters are a = 10.7917(9) , b = 10.4719(7) , c = 27.172(2) , = 97.754(3). The final reliability factor is R = 0.0448 for 4862 observed reflections and the goodness of fit is equal to 1.016. The bond distances and angles are in good agreement with the corresponding values for compounds containing phenyl and cholesterol moieties. The phenyl ring is planar and makes dihedral angles of 52.1(1) and 85.6(1) with the cholesterol segments. The cholesterol segments have the usual structure: rings A, C, E, G have chair conformation, and rings B, D, F, H adopt half-chair conformation. The molecules in the unit cell are arranged in layers. The crystal structure is stabilised by inter-molecular C-HO and C-H interactions.