화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.490, 80-87, 2008
X-ray structural analysis in the crystalline phase of a nematogenic fluoro-phenyl compound
Crystal and molecular structures of a nematogenic compound 4'-(3,4-difluoro pheiyl)-4-propyl-bicylohexyl (3ccp-ff) has been determined by direct methods using single crystal X-ray diffraction data. The compound (C-21 H-30 F-2) crystallizes in the monoclinic system with the space group P2(1)/n and Z= 4. The unit cell parameters are a 16.293(15) angstrom, b = 6.278(7) angstrom, c = 18.306(4) angstrom and beta - 96.84(6)degrees. The two cyclohexyl rings are almost coplanar, so also are the phenyl ring and the propyl chain. The cyclohexyl groups are in chair conformation. Imbricated mode of packing of the molecules is found in the crystalline state which is precursor to the nematic phase structure. Several close van der Waals interactions are found to exist between the neighbouring molecules. Short-range antiparallel type of association is found to exist between the neighbouring molecules in crystalline as well as in nematic phase.