Synthesis and characterization of a metal chelate-bridged quasi-ladder main chain discotic liquid crystal polymer

A metal chelate-bridged quasi-ladder discotic liquid crystal polymer (DLCP) has been prepared by a controlled chelation reaction of cupric ions with β-diketone groups on two adjacent poly(AADK-HMM) chains, synthesized by the hydrosilylation of a bis-allyl group-terminated β-diketone monomer and 1,1,3,3-tetramethylhydrodisiloxane (HMM). X-ray diffraction patterns of the samples annealed in the mesomorphic state or cooled from the isotropic phase demonstrated the existence of an ordered columnar structure on short or long range scales, respectively. The fact that the molecular weight of the cupric complex is approximately twice that of the parent polymer indicates that the quasi-ladder double chain polymer is the predominant product although some terminal defects are present.