Polymeric Phosphazenes

Linear phosphazene polymers, obtained from the reaction of ammonium chloride with phosphorus pentachloride in chlorobenzene, may be rendered hydrolytically stable by reaction of one of the terminal chlorine atoms with, for example, sodium phenoxide  

Dimethylamine, aniline, phenol, and ethanol have also been used with similar effect. 

The monophosphazenes, Cl3P=N PCOjClg, and PhaPCl N-PfOjCIa, give polymers of the type 

The properties of fluoroalkoxyphosphazene polymers and copolymers [N=P(OR)2ln (R- = fluoroalkoxy-group) have been described. Condensation of the phosphazenes, (Cl3PNPh)2 and C3N3(N=PCl3)3, with 

The reactions of chlorosilanes with alkoxyphosphazenes have already been mentioned (Section 3). This type of reaction has been exploited to obtain polymers containing 

Some indication of the increasing importance of this topic is provided by the number of review articles.141-146 

The formation of essentially linear polymers from N3P3C16 and/or N4P4C18 is catalysed by water147 and by (CF3S03)2Hg.148 Torsional braid analysis on 

Some of the properties of polymers derived from (NPC12)W and alanine152 and from arylamines153 have been described. The former are water-soluble and have potential medical applications. Molar refraction and volume data on NP(NHC6-H4R-p)2n (R = H, Me, OMe, or Cl) have been determined.154 

Of a series of phenylhalogeno-cyclotriphosphazatrienes, only N3P3F5Ph formed a homopolymer on heating.168 Ammonia can be usefully employed to effect the removal of hydrogen chloride in the condensation of polyols with (NPC12)W.169 

Terazawa, T. Kondo, andT. S. Suganama, Japan. Kokai 74 125626 Chem. Abs., 1975, 82, 157777). 

This increasingly important topic has been reviewed in general, - and in terms of specific applications of fluoroalkoxyphosphazene polymers. 

A further series of catalysts for the polymerization of N3P3CI8, including aluminium alkyls and alkoxy-derivativesof NaPaClg, has been proposed. Analysis of the non-polymer fractions soon after the initiation of polymerization of N3P8CI6 reveals 

Several new fluoroalkoxyphosphazene polymers have been synthesized and the conformational properties of these compounds explored, using the methods described in ref. 121. 

The properties of a fluoroalkoxyphosphazene rubber have been evaluated there 

The formation and properties - of aryloxyphosphazene polymers have received less attention than the analogous fluoroalkoxy-polymers. Polymers have 

129 -p Hayashi and H. Saito, Kogyo Kogaku Zasshi, 1971, 74, 22 Chem. Abs., 1971, 75, 5385n). 

NaPaCle 1.582 (5) 2.006 (3) 101.5 (1.5) Ca Symmetry (slightly puckered ring) indicated, which may be a vibrational effect rather than the equilibrium conformation 143 

Ring N atoms occupy four 151 of the five co-ordination sites at Co  

The reaction of alkoxyl radicals (generated by photolysis of nitrite esters) with phosphites has been exploited in a new synthesis of phosphates of hindered alcohols. Another aspect of this radical reaction which has been investigated, has been an evaluation of the ease of )8-cleavage of axial and 

---

Finally, substituted phosphoranimines seem to be able to avoid substitutional processes carried out on highly reactive polymeric phosphazene inter-... 

Allcock, H. R., and Brennan, D. J., Organosilicon derivatives of cyclic and high polymeric phosphazenes, J. Organomet. 

Allcock, H, R., and Scopelianos, A. G., Sjmthesis of sugar-substituted cyclic and polymeric phosphazenes, and their oxidation, reduction, and acetylation reactions. Macromolecules. 36. 715, 1983. 

On heating at ca. 160-200°C for 2-12 days, these phosphoranimines readily eliminate Me3S iOCH2CF3 (eq2) to form the polymeric phosphazenes, e.g., 1-4. Copolymers... 

Cyclic and High-Polymeric Phosphazenes as Carrier Molecules for Carboranyl, Metallo, or Bioactive Side Groups... 

Metallophosphazenes with Phosphorus-Metal Bonds. Until recently, the chemistry of cyclic and high polymeric phosphazenes was essentially the chemistry of their organic derivatives (Scheme 1). However, a discovery reported in 1979 (31) opened up a new field of metallophosphazene chemistry in which transition metals form the nucleus of the side group structure and are linked to the skeleton through phosphorus-metal bonds. These species are of theoretical and potentially practical importance, and I will summarize briefly some of the main features known at this time. 

In summary, this new and general method of synthesizing both cyclic and polymeric phosphazenes (eq 6)... 

Fig. 16.27 Polymeric phosphazenes (a) sLeroid-bound (b) sulfadiazine-bound ...

Cyclic and polymeric phosphazenes will form water-soluble platinum(II) complexes. The compounds contain square planar platinum bonded to the phosphazene via nitrogen.1503-1506... 

Figure 3.5 Schematic representation of the effect of steric hindrance generated by bulky side groups on a cyclic trimeric and a high polymeric phosphazene. Depolymerization of a high polymer to a cyclic trimer relieves the intramolecular crowding.

Cyclophosphazene derivatives, (NPR2)4 (R = Me, NHMe) and the polymeric phosphazene, [NP(NHMe)2] react with K2PtCl4 in organic media to yield square-planar complexes, (NPR2)4 PtCl2 and a product... 

The polymeric phosphazenes are treated in chapter (see Polyphosphazenes) A recent monograph covers the chemistry of polyphosphazenes (nomenclature, synthesis of cyclic monomers , ring opening polymerization, condensation polymerization, substitution, polymer properties, and applications more than 1000 literature citations). Other reviews have also been published recently. Sulfur-containing polyphosphazenes have also been described. ... 

The chioro-triazadiphosphinines are readily soluble in a variety of solvents, such as dichloromethane or toluene. Compared to (NPCl2)3 they are more sensitive to moisture. At high temperature (—250°) they decompose, losing nitrile and forming a polymeric phosphazene. This decomposition may in certain cases be used to initiate the polymerization of a cyclophosphazene. Nucleophilic substitution converts the chioro-triazadiphosphinines to partially or completely amino-, alkoxy-, or aroxysubstituted derivatives. " ... 

ORGANOSILICON DERIVATIVES OF CYCLIC AND HIGH POLYMERIC PHOSPHAZENES... 

Species that combine the properties of organosilicon compounds and phos-phazenes are prepared by the linkage of organosilicon side groups to a small molecule cyclic or linear high polymeric phosphazene skeleton. This is particularly important for high polymeric derivatives in which hybrid properties typical of polysiloxanes (silicones) and polyphosphazenes - may be obtained. 

---