Synthesis of novel liquid crystalline organometallic polymers

The synthesis and some properties of organometallic homo- and copolymers carrying diethynylated pi-complexes are discussed. As monomers the diethynylated derivatives of cymantrene and cyclopentadienyl(1,3-bistrimethylsilylcyclobutadiene)cobalt were utilized. Novel thermotropic nematic and lyotropic smectic liquid crystalline polymers were synthesized as copolymers of 1 and 2,5-dihexyl-1,4-diiodobenzene or 3-hexyl-2,5-diiodothiophene in a Cassar-Heck-Hagihara coupling reaction. The liquid crystalline behavior was secured by polarizing microscopy and powder X-ray diffractometry.