Ferrocene-based polymers containing azo groups in their backbone: Synthesis, electrochemical and thermal analysis.

Ferrocene-based polymers contg. azo groups in their backbone were synthesized by condensation polymn. of a cationic organometallic monomer contg. two azo dye moieties and ferrocene in the backbone as well as pendent cationic iron groups with 1,3-diaminopropane, 4,4'-thiobisbenzenethiol or bisphenol A in the presence of K2CO3. The pendent cationic cyclopentadienyl moieties were then photolytically removed from the polymers yielding neutral polyferrocene analogs. The neutral polyferrocenes had mol. wts. ranging from 8000-12,000. Thermogravimetric anal. of the cationic polymers showed two defined wt. losses, with degrdn. of the azo dye overlapped with the loss of the cyclopentadienyliron moiety at temps. between 210°-300° and degrdn of the polymer backbone at 400°-500°. The neutral polyferrocenes displayed a wt. loss assocd. with the degrdn. of the azo dye around 210°-300°. Degrdn. of the polymer backbone occurred between 400°-500°. The cationic polymers showed glass transition temps. between 126°-164°, whereas the neutral polymer displayed glass transition temps. at significantly lower temps., i.e., 85°-92°. UV-visible studies of the polymers showed they displayed a λmax similar to that of the unreacted azo dye. [on SciFinder(R)]