X-Ray Structural Analysis in the Crystalline Phase of a Nematogenic Fluoro-Phenyl Compound

Abstract

Crystal and molecular structures of a nematogenic compound 4′-(3,4-difluoro phenyl)-4-propyl-bicyclohexyl (3ccp-ff) has been determined by direct methods using single crystal X-ray diffraction data. The compound (C21 H30 F2) crystallizes in the monoclinic system with the space group P21/n and Z = 4. The unit cell parameters are a = 16.293(15) Å, b = 6.278(7) Å, c = 18.3064) Å and β – 96.846)°. 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.