SYNTHESIS AND MESOMORPHIC PROPERTIES OF FISHBONE-LIKE LIQUID CRYSTALLINE POLYSILSESQUIOXANES——Ⅰ. FISHBONE-LIKE, β-DIKETONE-BASED LIQUID CRYSTALLINE POLYSILSESQUIOXANES AND THEIR COPPER COMPLEXES

Two kinds of fishbone-like, β-diketone-based liquid crystalline polysilsesquioxanes（FBDKLCP’S）, homopolymeric （H-FBDKLCP） and copolymeric （C-FBDKaLCP） have been first synthesized via the hydrosilylation reaction of a vinyl-terminated β-diketone with the homopolymeric ladderlike polyhydrosilsesquioxane （LPHSQ） and random copolymethylhydrosilsesquioxane （LRPMHSQ） respectively. These new kinds of FBDKLCP with M of 104 is thermotroic liquid crystalline polymer and its clearing temperatures Ti’s and mesophase range △T’s are much higher than those of the corresponding comb-like β-diketone liquid crystalline polysiloxane （DKLCP） by about 200℃. Similar results have been observed with the comparison of the two different structure Cu-coordinating compounds The significant increases in T（?）’s and △T’s of the FBDKLCP and Cu-FBDKLCP are mainly attributed to the great rigidity of the ladderlike polysilsesquioxane backbone.