Metallocenophane, silicon

Silicon-bridged [l,l]metallocenophanes of type 40 in Scheme 14 represent another class of dinuclear compounds with the ligand system (30). The synthesis of the 1,1,12,12-tetramethyl [1,1] silaferrocenophane was reported by two groups only recently. In one procedure, the dilithium salt of dicyclopentadienyldimethylsilane was reacted with ferrous chloride to give a mixture of the metallocenophane with poly(ferrocenyldimethylsilane) (equation 55)124. In the other procedure, this compound was prepared in a multistep synthesis starting from dilithio ferrocene, as shown in equation 56125... 

Thermal ROP of silicon-bridged [1 Jferrocenophanes Thermal ROP of other strained metallocenophanes Living anionic ROP of strained metallocenophanes Transition metal-catalyzed ROP of strained metallocenophanes Other ROP methods for strained metallocenophanes Properties of polyferrocenylsilanes... 

The thermal ROP methodology established for silicon-bridged [I]ferrocenophanes has been extended to many other strained metallocenophanes, which allows access to high molecular weight polyferrocenes with different spacer groups. As discussed later (see Section 12.06.3.3.6), this permits modification of the properties of the polymer, such as the extent of the metal-metal interactions. 

Anionic ROP reactions of metallocenophanes were first reported in Silicon-bridged [I]ferrocenophanes 72... 

Fig. 25, Some metallocenophanes containing silicon bridges and the heterobimetallic complex 116 an alternate approach to an organometallic polymer [99-101]...

The first examples of the use of ROP of strained metallocenophanes to prepare high molecular weight polymetallocenes (Mn>10 ) involved silicon-bridged [Ijferrocenophane monomers 3.21 [61]. Specifically, polyferrocenylsilanes (PFSs) 3.22 (R,R = Me or Ph) were prepared by the thermal ROP of strained, ring-tilted silicon-bridged [l]ferrocenophanes 3.21 (R,R = Me or Ph) in the melt, at 130-... 

Since the discovery of the ring-opening polymerization of strained metallocenophanes, a diverse series of metal-containing macromolecules have been synthesized and characterized (see Scheme 4). These include the following variations substituents on silicon, munber and type of bridging atoms, and substituents on the cyclopentadienyl rings. ... 

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