Synthesis and mesomorphic properties of fishbonelike,liquid crystalline polysilsesquioxanes: 4. Pd-coordinating,fishbone-like imine-based liquid crystalline polysilsesquioxane

A new type of Pd-coordinating, imine-based, fishbone-like liquid crystalline polysilsesquioxanes (Pd-FBI) including μ-acetato-bridged Pd-FBI Pd(μ-oAc)-FBI] and μ-chloro-bridged Pd-FBI Pd(μ-Cl)-FBI] has been synthesized first by a hydrosilylation reaction to form fishbone-like, imine-based liquid crystalline polysilsesquioxane (H-FBI and MH-FBI respectively,) and then by an ortho-palladation reaction with palladium acetates to obtain Pd(μ-oAc)-FBI. The latter was further subjected to ligand substitution reaction with NaCl to form Pd(μ-Cl)-FBI. Their mesomorphic properties investigated by differential scanning calorimetry (DSC) and optical polarization microscopy (OPM). show that the Pd-FBI is a thermotropic liquid crystalline polymer and its clearing temperatures and mesophase range are much higher than those of the corresponding comb-like imine liquid crystalline polysiloxanes (IMLCP) by about 100 °C. In this paper the influence of the palladium content on mesogenic behavior is discussed.