Crystal and molecular structure of 4'-hexyloxyphenyl 4-pentylbenzoate

The molecular and crystal structure of 4′-hexyloxyphenyl 4-pentylbenzoate, C6H13O-C6H4-COO-C6H4-C5H11, which is a liquid-crystal compound, was determined by X-ray diffraction. This compound forms a nematic phase upon melting. The crystal contains three crystallographically independent molecules. In one of them, the alkyl chain is disordered. This is indicative of the looseness of the crystal packing in the aliphatic region. The crystal structure is stabilized by the following two types of weak directional interactions: hydrogen bonds with the participation of the terminal O atom of the ester group and the C-H group of one of the benzene rings and C-H…π-system interactions. Only one of the three independent molecules is involved in the latter type of interactions. Hence, the structurization of the mesophase is most likely determined by hydrogen bonding.