Polymerisation of Phosphacyclic Monomers

An interesting example of the coordination polymerisation of a phosphacyclic monomer is represented by the polymerisation of oxyphosphonoyloxytrimethy-lene (2-hydro-2-oxo-l,3,2-dioxaphosphorinane) in the presence of triisobutyla-luminium as the catalyst [181,182], This polymerisation, carried out at a temperature of 25 °C, produced, in relatively high yield, poly(oxyphosphonoy-loxytrimethylene) which appeared to be a high molecular weight polymer (Table 9.2). 

There is rather scant information in the literature that might indicate the mechanism operating in the polymerisation of oxyphosphonoyloxytrimethylene with triisobutylaluminium. It seems most likely, however, that the propagation step involves ring opening at the P-0 bond of the coordinating monomer, leading to the aluminium alcoholate species, as illustrated schematically below  

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