Group 13 Lewis acid adducts of [PCl2N]3

Phosphazene polymers are classically synthesized by the high-temperature, ring-opening polymerization (ROP) of PCl(2)N](3) to give PCl(2)N](n), followed by functionalization of PCl(2)N](n) with different side groups. We investigated the interactions of PCl(2)N](3) with Lewis acids because Lewis acids have been used to induce the high-temperature ROP of PCl(2)N](3). The reactions of PCl(2)N](3) with MX(3) (M = group 13, X = halides), under strict anaerobic conditions gave adducts PCl(2)N](3)·MX(3). Adducts were characterized by X-ray crystallography and multinuclear and variable-temperature NMR studies, and mechanistic understanding of their fluxional behavior in solution was achieved. The properties of the PCl(2)N](3)·MX(3) adducts at or near room temperature strongly suggests that such adducts are not involved directly as intermediates in the high-temperature ROP of PCl(2)N](3).