Ring-opening polymerization silicon-bridged

III. Ring-Opening Polymerization of Silicon-Bridged [IIFerrocenophanes. 136... 

RING-OPENING POLYMERIZATION OF SILICON-BRIDGED [1]FERROCENOPHANES... 

Prior to 1992 no efforts to prepare polymers with main chains consisting of ferrocene and organosilane units via ring-opening methods had been reported. The first developments in this area involved attempts to polymerize silicon-bridged ferrocenophanes and related species (23,41). The first successful ROPs involved the use of [l]silaferrocenophanes as cyclic monomers, and the progress in this area to date together with relevant previous work is now reviewed. 

The discovery of the anionic ring-opening polymerization of silicon-bridged[l]ferrocenophanes enabled the synthesis of well-defined, near-monodisperse poly(ferrocenylsilane) homo- and block copolymers. PFS was combined with polystyrene [38], polyisoprene [39], poly(dimethylsilox-ane) [40], poly(ethylene oxide) [41], poly(ferrocenylphenylphosphine) [42], poly(aminoalkyl methacryate) [43] and recently with poly(methyl methacrylate) [44,45] blocks. 

Cyclic, silicon-bridged [l]ferrocenophanes have been found to undergo thermal ring-opening polymerization to afford high-molecular-wei t poly(ferrocenylsilane)s (see Eq. 1.31) [8, 43]. Many other members of this family of polymers are now known including those where the silicon center is replaced by Sn(IV), P(III), Ge(IV), B(III) etc., [8],... 

The relief of ring-strain present in silicon-bridged ferrocenophanes can be utilized as the driving foree for its ring-opening polymerization (ROP). Manners and coworkers have shown that it is possible to induce the ROP of silicon-bridged ferrocenophanes by at least three different synthetic approaches [3,7,44-46], These are (a) thermal ROP (b) anionic ROP and (c) transition-metal-complex eatalyzed ROP. 

Thermal Ring-opening Polymerization of Silicon-bridged Ferrocenophanes... 

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. ... 

TAN 04] Tanabe M., Manners 1., photolytic living anionic ring-opening polymerization (ROP) of silicon-bridged [Ijferrocenophanes via an iron-cyclopentadienyl bond cleavage mechanism . Journal of American Chemical Society,vo. 126, pp. 11434-11435,2004. 

Temple K, JaMe F, Sheridan JB, Manners 1 (2001) The nature of the active catalyst in late transition metal-mediated ring-opening polymerization (ROP) reactions mechanistic studies of the platinum-catalysed ROP of silicon-bridged [l]ferrocenophanes. J Am Chem Soc 123 1355-1364... 

Pudelski JM, Manners I (1995) A heterolytic cyclopentadienyl carbon-silicon bond cleavage mechanism for the thermal ring-opening polymerization of silicon-bridged [l]ferroceno-phanes. J Am Chem Soc 117 7265-7266... 

Bartle-Scott A, Resendes R, Manners I (2003) Transition metal-catalyzed ring-opening polymerization of silicon-bridged [l]ferrocenophanes in the presence of functional silanes molecular weight control and synthesis of telechelic poly(ferrocenylsilanes). Macromol Chem Phys 204 1259-1268... 

Gomez-Elipe, P., Resendes, R., Macdonald, P.M., and Manners, I. (1998) Transition metal catalyzed ring-opening polymerization (ROP) of silicon-bridged [l]ferrocenophanes facile molecular weight control and the remarkably convenient synthesis of poly(ferrocenes) with regioregular, comb, star, and block architectures. Journal of the American Chemical Society, 120,8348. 

The transition-metal-catalyzed ring-opening polymerization of silicon-bridged, strained, ring-tilted ferrocenophans yields polyferrocenylsilanes with intriguing properties. ... 

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