Single-chain elasticity of poly(ferrocenyldimethylsilane) and poly(ferrocenylmethylphenylsilane)

AFM-based single-molecule force spectroscopy (SMFS) is a powerful tool for the investigation of the elastic properties of a single polymer. Two typical organometallic polymers bearing ferrocene (Fc) groups in the backbone, poly(ferrocenyldimethylsilane) and poly(ferrocenylmethylphenylsilane), were investigated by SMFS to reveal their single-chain mechanical properties in normal and oxidized forms. We have found that the two polymers show similar elasticity in normal forms, though bearing different side groups. However, they exhibit different enthalpic elasticity after oxidation probably because of steric effects. Moreover, all experiments confirm that the single-chain elongation of poly(ferrocenyldimethylsilane) or poly(ferrocenylmethylphenylsilane) is reversible.