Synthesis and characterization of polyhedral oligomeric azido‐octaphenylsilsesquioxane

Abstract Polyhedral oligomeric azido‐octaphenylsilsesquioxane (N 3 ‐OPS) was synthesized from octaaminophenylsilsesquioxane (OAPS) via its diazonium salt. The synthesis included nitration of octaphenylsilsesquioxane (OPS) to octanitrophenylsilsesquioxane (ONPS), conversion of ONPS into octaaminophenylsilsesquioxane (OAPS), and conversion of OAPS into N 3 ‐OPS. The kinetics of the conversion of OAPS into N 3 ‐OPS were studied by recording the volume of N 2 gas released with the reaction time, which revealed it to be a 1st order reaction. The chemical structures of ONPS, OAPS and N 3 ‐OPS were characterized by 1 H‐NMR, GPC, FTIR, 29 Si solid NMR, 13 C‐NMR, XRD, and elemental analysis. It is proposed that the diazonium salt of OAPS was substituted by the main N 3 group and a few of the OH groups. The ratio of N 3 :OH was calculated to be approximately 68:32 in N 3 ‐OPS on the basis of the elemental analysis and 1 H‐NMR. XRD suggested that N 3 ‐OPS was a kind of amorphous compound. The two‐step conversion mechanism of OAPS to N 3 ‐OPS was briefly discussed. TGA results showed that N 3 ‐OPS was stable at ambient temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012