METALLORGANIC SIDE-GROUP LIQUID-CRYSTALLINE POLYMERS CONTAINING PI-ALLYLPALLADIUM(II) GROUPS

The preparation and phase properties of some LC pi-allyl and pi-crotyl Pd(II) side group metallorganic polymers and some related salicylaldi minates are described. The LC acrylate functionalized monomers are eas ily prepared, but their use to obtain the corresponding polymers by ra dical reaction failed because extensive decomposition of the complexes occurs with the formation of Pd metal. The synthesis of the metallate d polymers was therefore performed by reacting the dimeric chloro-brid ged organometallic pi-allyl or pi-crotyl Pd(II) complexes with the app ropriate ligand polymer which is prepared without difficulties. The or ganometallic polymers show a nematic mesophase, while the ligand polym er exhibits a smectic A or C phase. Both metallated low molecular mass model compounds and the polymers give stable mesophases, although at lower temperatures compared with the parent ligand compounds.