Polybis(pyrrolyl)phosphazene.

In the present article for publication in the ACS Symposium Series we summarize our progress in the synthesis and characterization of pyrrolylphosphazenes. The preparation of these compounds requires use of the pyrrolide nucleophile and it is found that the nature of the substrate, as well as the reaction conditions exert a profound effect on the outcome of these reactions. The cyclic trimer (NPCl sub 2) sub 3 is well-behaved under a fairly broad spectum of reaction conditions, but the high polymer (NPCl sub 2) sub x is susceptible to chain cleavage and cross-linking. Nevertheless, under carefully controlled conditions full substitution of the precursor polymer may be achieved, leading to polybis(pyrrolyl)phosphazene (PBPP). Efforts to induce electronic conductivity in the polyphosphazenes are reviewed, with particular emphasis on PBPP which exhibits conductivity on oxidation, or better, on heat treatment, presumably as a result of cross-linking.