Polymerization of Diphenylacetylenes Having a Ferrocenyl Group and Polymer Properties

Abstract

Polymerization of two diphenylacetylenes having a ferrocenyl group at para or meta position, 1-[p-ferrocenylphenyl]-2-phenylacetylene (p-FcDPA) and 1-[m-ferrocenylphenyl]-2-phenyl-acetylene (m-FcDPA) and properties of the formed polymers were investigated. Both monomers polymerized with TaCl₅-n-Bu₄Sn catalyst in good yields to give reddish brown polymers. Poly(p-FcDPA) was insoluble in any solvents. On the other hand, poly(m-FcDPA) was soluble in CHCl₃, THF, anisole, o-dichlorobenzene, and so on, and its weight-average molecular weight (M _w) was 53×10⁴ and fairly high. A free-standing film of poly(m-FcDPA) could be easily fabricated by solution casting. The onset temperature of weight loss (T ₀) of poly(m-FcDPA) in air was ca. 310°C, indicating moderate thermal stability. Poly(m-FcDPA) was electrochemically active, and showed redox cycles based on the ferrocene moiety in cyclic voltammetry.

Keywords:

• Metal-containing polymer
• Substituted polyacetylene
• Ferrocene
• Metathesis polymerization
• Transition metal catalyst
• Redox-active polymer

Acknowledgments

MT acknowledges the support by JSPS Research Fellowships for Young Scientists.