Comparison of the Crystal and Molecular Structures of Three Similar 4-Heptyl-biphenyl Compounds: 4-Heptyl-4′-cyanobiphenyl, 4-Heptyl-3′-cyanobiphenyl, and 4-Heptyl-4′-nitrobiphenyl

Abstract

The structure of 4-heptyl-4′-cyanobiphenyl (7CB4), 4-heptyl-3′-cyanobiphenyl (7CB3), and 4-heptyl-4′-nitrobiphenyl (7NB4) have been investigated at 22°C in the crystalline phase to gain insight into the influence of packing arrangements by intermolecular interactions and of conformation of similar compounds by varying the terminal part of the molecule. The compound 7CB4 exhibits a nematic liquid-crystalline phase that is not present for the other two compounds. The packing of the three compounds is quite different, although two of them belong to the same space group, P21/a.