Variable temperature 57Fe Moessbauer studies on polymers of vinylferrocene and 1,1'-divinylferrocene

Variable temperature 57Fe Moessbauer spectra have been recorded in the range 80-300 K for a number of low molecular weight amorphous polymers containing ferrocene units. These include samples of polyvinylferrocene, polydivinylferrocene by anionic initiation and polydivinylferrocene by cationic initiation. A similar non-linear temperature dependence of lnA was observed for all the polymers, although they contain ferrocene units in different structural arrangements. A Debye model was extended to include intramolecular vibrations, and a fit to the experimental data was obtained. However, the model did not yield satisfactory fitting parameters. The observed behaviour of the experimental data could be accounted for by assuming that each macromolecule vibrates within an anharmonic potential. (Auth.)