Reaction of m-terphenyldichlorophosphanes with sodium azide: synthesis and characterization of stable azidocyclophosphazenes

Reaction of the m-terphenyldichlorophosphanes 2,6-(2-MeC(6)H(4))(2)C(6)H(3)PCl(2) (1), 2,6-(4-t-BuC(6)H(4))(2)C(6)H(3)PCl(2) (2), or 2,6-Mes(2)C(6)H(3)PCl(2) (3) with excess NaN(3) in acetonitrile at room temperature afforded the corresponding bisazidophosphanes 2,6-(2-MeC(6)H(4))(2)C(6)H(3)P(N(3))(2), 2,6-(4-t-BuC(6)H(4))(2)C(6)H(3)P(N(3))(2) (5), or 2,6-Mes(2)C(6)H(3)P(N(3))(2) (6) (Mes = 2,4,6-Me(3)C(6)H(2)), respectively. These compounds are thermally labile and decompose into a number of azidophosphazenes. The azidocyclophosphazenes NP(N(3))(C(6)H(3)(4-t-BuC(6)H(4))(2)-2,6)](3) (4) and NP(N(3))C(6)H(3)Mes(2)-2,6](2) (8) have been isolated from these mixtures. All compounds were characterized by (1)H, (13)C, (31)P NMR and IR spectroscopy. Crystal structures of 2, 4, and 8 were determined.