Inclusion compounds of cyclodextrin and azo dyes. Formation of a liquid crystal.

An aqueous solution of orange II and γ-cyclodextrin forms a lyotropic mesophase at room temperature. Nuclear magnetic resonance and circular dichroism suggest that the mesophase is formed from the inclusion compound which has a 1 : 1 structure and that orange II enters γ-cyclodextrin mainly from the long axis side of the molecule. Moreover this side aligns perpendicular to the magnetic field.