Cyclic and high molecular weight chiral binaphthoxy-phosphazene polymers carrying Br or trimethylsilyl-acetylene groups

The new chiral and functionalized cyclic binaphthoxyphosphazenes R,R,R-N₃P₃(O₂C₂₀H₁₀Br₂)₃] (R-1), R,R,R-N₃P₃(O₂C₂₀H₁₀(CCSiMe₃)₂)₃] (R-2), and the high molecular weight linear polymers R/S-NP(O₂C₂₀H₁₀Br₂)]_n (R/S-3), R-NP(O₂C₂₀H₁₀Br₂)]_n (R-3), and R-{NPO₂C₂₀H₁₀(CCSiMe₃)₂]}_n, (R-4), with M_w on the order of 10⁶ and very high T_g, have been synthesized and characterized by IR and NMR spectroscopy. The optically active polymer (R-3) was configurationally stable below 300 °C, but at higher temperatures an atropisomerization process took place that became faster near the glass transition temperature (ca. 350 °C).