A Heterolytic Cyclopentadienyl Carbon—Silicon Bond Cleavage Mechanism for the Thermal Ring-Opening Polymerization of Silicon-Bridged [1]Ferrocenophanes

摘要

High molecular weight polymers containing skeletal transition metal atoms are attracting increasing attention because of their interesting properties, but in general, synthetic routes to these materials are poorly developed. With this in mind, in 1992 we reported the discovery that strained, ring-tilted silicon-bridged [1]ferrocenophanes (e.g., 1) undergo thermal ring-opening polymerization (TROP) to afford soluble, high molecular weight poly(ferrocenylsilanes) (e.g., 2). We have subsequently extended this TROP methodology to [1]ferro-cenophanes containing germanium and phosphorus in the bridge, and also to hydrocarbon-bridged [2]metallocenophanes. Studies of the resulting transition metal-containing polymers have revealed that these materials possess a variety of interesting electrochemical, preceramic, morphological, and, when oxidized, magnetic properties.