Calix[4]resorcinarene-cholesterol columnar liquid crystals: Synthesis, mesomorphism and the influence of spacers on liquid crystalline behaviors

Novel calix[4]resorcinarene derivatives with four cholesterol units bridging by soft spacers or rigid Schiff-base spacers were prepared in yields of 63-76%. The hexagonal columnar liquid crystalline behaviors were firstly observed for calix[4]resorcinarene derivatives. The mesomorphic properties were influenced greatly by the structures of spacers. The rigid spacers were favorable for enhancing the phase transition temperatures and enlarging the temperature scopes of mesophase.