Crystal and Molecular Structure of Nematogenic 4′- n-butyl-4-cyanobiphenyl (4CB)

The crystal and molecular structure of 4′- n-butyl-4-cyanobiphenyl (4CB), C17H17N, has been determined at room temperature. The compound, which exhibits a monotropic nematic phase, crystallizes in the monoclinic space group P21,/ c, a = 12.198, b = 9.204, c = 14.746 Å, β = 123.38°, with four molecules in the unit cell. The structure has been refined to R = 0.136 using photographically observed data. The terminal part of the butyl chain is disordered. The 4CB molecules pack in a sheet-like arrangement, with nearest neighbors oriented antiparallel to each other. The angle between the phenyl rings is 40°30′.