The molecular and crystal structure of bipolar, mesogenic biphenyls: a comparison of similar compounds HO(CH 2) 6 OC 6 H 4 C 6 H 4 R with R = cyano and nitro terminal groups

Abstract

The crystal and molecular structures of 4,4′-disubstituted biphenyls of formula HO(CH₂)₆ OC₆H₄C₆H₄ R with R = cyano and nitro terminal groups have been determined including co-crystallized materials of both of the compounds. The extended molecules arrange in an antiparallel fashion with dipole-dipole interactions, exhibiting a sheet-like structure for the compound with the cyano terminal group, and for the other two materials an extended head to tail string-like structure caused by dipolar interaction, also packed in sheets in an antiparallel fashion by van der Waals interactions. Knowledge of the interaction of the compounds in the crystalline state serves as a prerequisite for the determination of interactions in the liquid crystalline state of the same or similar compounds.