Phosphazenes cyclic

Third, metallocene units, such as ferrocene or ruthenocene, have been linked to phosphazene cyclic trimers or tetramers and these were polymerized and substituted to give polymers of the type mentioned previously (41). Polyphosphazenes with ferrocenyl groups can be doped with iodine to form weak semiconductors. Polymer chains that bear both ruthenocenyl and ferrocenyl side groups are prospective electrode mediator systems. 

The emphasis in the following sections will be on exploratory model reactions carried out with phosphazene cyclic trimers or tetramers, although the analogous macromolecules systems have also been studied in several cases. First, I will summarize the various types of metal binding sites that are accessible at the present time. Synthetic procedures leading to the incorporation of several of these sites and their role in metal binding will then be discussed. 

Linear poly(organophosphazenes) are now synthesized by six different methods. These are (a) The ring-opening polymerization of (NPC12)3 mentioned above, followed by macromolecular substitution (b) Ring-opening polymerization of organic substituted phosphazene cyclic trimers, usually followed by macromolecular substitution ... 

Deiters 1977, Robinet 1989,1991, Ugliengo 1989, Gasmi 1991 Phosphazenes (cyclic)... 

Polymers with different groups attached to the phosphorus atom can be obtained from phosphazene cyclic trimers or tetramers with mixed halogen and alkyl or aryl side groups by a similar procedure. Further attachment of side groups, such as fluoroalcoxy, can be achieved by treatment of the polymer with excess of sodium fluoroalkoxides [2], By this procedure are obtained, for example, poiy fluoroaikoxyphosphazenes) with the structure shown below ... 

A new route to poly(organophosphazene)s has been reported in which the phosphazene cyclic trimer [NP(OCHjCF3)2J3 is copolymerized with (NPa )3 to yield a new series of rubbers. The copolymers have been characterized by means of substitution reactions and P n.m.r. analysis. The synthesis of resins by the... 

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