Cyclo- and Polyphosphazenes

An organic polymer containing a cyclophosphazene ring as a pendant group 

There are many other polymers that are related to the polyphosphazene family. Thus, there are polymers which are actually made up of an organic backbone but contain a cyclophosphazene ring as a pendant group appended in their side chain. Other polymers that are related to polyphosphazenes are those that contain a third hetero atom in the backbone. Examples of such polymers are shown in Fig. 3.2. 

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Transition metals have been linked to cyclo- and polyphosphazenes by four different methods. First, and most obvious, the linkage makes use of the coordinating power of the backbone nitrogen atoms. The platinum dichloride adduct (referred to earlier) falls into this category. 

Perhaps the most widely studied of the dehydrochlorination syntheses are the reactions of halophosphoranes with ammonia to form cyclophosphazenes. This is the classic route from which nearly all cyclo- and polyphosphazene chemistry is derived. Both halogeno- and organocyclophosphazenes have been prepared by this method ... 

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