Polymers polymetallocenes

Cuadrado and co-workers prepared polysiloxanes with ferrocene and cobalticenium moieties in their backbone.180,181 Polymetallocene, 94, was synthesized by reacting l,3-bis(3-aminopropyl)-l,l,3,3-tetramethyldisiloxane with 1,1 -bis(chlorocarbonyl)ferrocene or 1,1 -bis(chlorocarbonyl)cobalticenium hexafluorophosphate. The organoiron polymer displayed a Mn = 10,600,180 whereas the organocobalt polymer possessed very low solubility in polar organic solvents.181 An alternative preparative route to this class of polymer is the reaction of l,l -bis((3-aminoethyl)ferrocene with dimethylbis(4-chlorocarbonylphenyl) silane.180... 

Side-chain Polymetallocene Homopolymers and Block Co-polymers... 

Properties of other ring-opened polymetallocenes and related materials Polyferrocenylsilane block co-polymers Polyferrocenylphosphine block co-polymers... 

ROP reactions generally occur by a chain-growth mechanism (Chapter 1, Section 1.5.2.2.3) and therefore represent a particularly desirable route for the preparation of high molecular weight polyferrocenes. As is clear from the polymers described so far in Sections 3.1 and 3.2, such materials are rare if the ferrocene groups are in close proximity to one another so as to permit substantial metal-metal interactions. The first syntheses of polymetallocenes by ROP methods were reported in early 1992. A novel atom-abstraction-induced ROP process for [3]trithiaferroce-nophanes was described early in that year and these results are discussed in Section 3.5 [60]. Thermal ROP of strained metallocenophanes, which is discussed in this section, was reported a few months thereafter [61]. 

Thermal ROP of metallocenophanes leads to virtually no control over molecular weight and the molecular weight distribution is broad (PDI= 1.5-2.5). Subsequently, living anionic and transition metal catalyzed ROP routes to polymetallocenes have been developed. " These have permitted unprecedented control of mainchain metal-containing polymer architectures. In particular, the access provided to the first block copolymers with metals in the mainchain has created unique opportunities for the generation of self-assembled, supramolecular materials. 

Polymetallocenes with acetylene emits in their backbones have been synthesized through reactions of diiodoferrocenes with diethynyl monomers, as shown in scheme These polymers, formed through palladium-catalyzed reactions, displayed semiconducting properties upon doping with iodine. The iodine adduct of polymer 28a exhibited an electrical conductivity of 1.3 X 10 " S/cm, while 28b was resistant to oxidation. ... 

Research in metallocene-containing polyamides, polyureas, polyuretiianes, and polyesters continued to be conducted in the 1980s, and since that time, research into these classes of materials has continued to grow7 Homoannular and heteroaimular liquid-crystalline polymetallocenes have been prepared by Zentel and coworkers through condensation reactions. Ferrocene-based liquid-crystalline polymers have also been reported by Senthil and Kannan. The synthesis of ferrocene polymers containing backbone organophosphorus moieties 32 is shown in scheme 9. 

Rosenblum and coworkers reported the synthesis of face-to-face polymetallocenes via the methodology described in scheme 16. Paramagnetic mixed-metal polymers containing nickel and iron or cobalt and iron were also synthesized. The magnetic moments of these polymers were 5.3 and 5.2 /Xb, respectively. 

Rosenblum and cowoikers have described a number of routes to lace-to-lace polymetallocenes. Ruthenium- and iron-based materials were synthesized via palladium-catalyzed cross-coupling reaction of 1,8-diiodonaphthalene with metallo-cenylzinc chloride (M=Fe, Ru). The MW of the face-to-lace polyferrocenes with R=H,R = 2-octylwasintherangeof 18,000, while that of200 when R=R =2-octyl, was 139,000. The conductivity of polymer 200 (M=Fe, R=H, R =2-octyl) on doping with I2 was 6.7 X 10 S/cm. The incorporation of nickelocene and cobaltocene units into the fece-to-lace polyferrocenes resulted in materials with magnetic susceptibilities of 3.51 and 5.2 (1 for the Ni Fe and Co Fe ohgomers, respectively. ... 

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