CRYSTAL-STRUCTURES OF 60CB AND 70CB

Crystal structures of title compounds have been determined by single crystal x-ray analysis. Crystal data. 4'-Hexyloxy-4-cyanobiphenyl (60CB), [GRAPHICS] M(r) = 279.37, monoclinic, P2(1)/a, T = 298 K, a = 26.76(1), b = 7.609(3), c = 16.636(7) angstrom, beta = 105.52(3)degrees, V = 3263(2) angstrom3, Z = 8, d(x) = 1.142 g cm-3, mu(Mo Kalpha) = 0.37 cm-1, F(000) = 1200; 4'-Heptyloxy-4-cyanobiphenyl (7OCB), [GRAPHICS] M(r) = 293.39, triclinic, P1BAR, T = 298 K, a = 12.6556(8), b = 19.044(2), c = 7.3495(5) angstrom, alpha = 94.142(8), beta = 100.108(5), gamma = 91.036(7)degrees, V = 1738.4(2) angstrom3, Z = 4, d(x) = 1.125 g cm-3, mu(Cu Kalpha) = 4.58 cm-1, F(000) = 632. Molecular structures in both crystals are very similar with twisted biphenyl moieties and fully extended paraffin chains. Dimers are formed by close contacts of CN groups between neighboring molecules (C-N: 3.56 and 3.40 angstrom for 6OCB and 3.55 and 3.39 angstrom for 7OCB). The neighboring dimers in 6OCB are overlapped half-and-half, while those in 7OCB are arranged in a smectic-like layer structure.