Synthesis of soluble cobaltacyclopentadiene oligomers and polymers

Summary form only given. Transition metal complex polymers involving highly and linearly /spl pi/-conjugated organic moieties have a possibility to show novel physical and chemical properties based on electronic interaction between /spl pi/-electrons (orbitals) and d-orbitals (electrons). Our previous study has shown that successive addition reaction of 4,4´-diethynylbiphenyl to CoCp(PPh/sub 3/)/sub 2/] gives a /spl pi/-conjugated organometallic polymer, poly(4,4´-biphenylene 2,5-cobaltacyclopenta-2,4-dienylene) as an insoluble material. We report here a study on the synthesis of soluble cobaltacyclopentadiene oligomers and polymers. The soluble oligomers and polymers, HC/spl equiv/C-C/sub 6/H/sub 4/{C/sub 4/H/sub 2/[Co(hexyl-Cp)(PPh/sub 3/)]-C/sub 6/H/sub 4/}nC/spl equiv/CH, were obtained by a reaction of [Co(hexyl-Cp)(PPh/sub 3/)/sub 2/] with p-diethynylbenzene. The n-hexyl group introduced in Cp ring increases the solubility of the polymers in common organic solvents such as toluene. The products were separated with a recycling preparative HPLC apparatus into several oligomers and a polymer. Characterization and electrochemical properties of the products will be reported.