SYNTHESIS AND CHARACTERIZATION OF METALLOPHOSPHAZENE DERIVATIVES - SOLUTION-STATE AND SURFACE-REACTIONS

The small-molecule cyclotriphosphazenes N3P3(OPh)5OC6H4R and N3P3(OC6H 4R)6 where R = FeCP(CO)2 were synthesized by reaction of the correspon ding [ (lithioaryl)oxy]phosphazenes with cyclopentadienyliron dicarbon yl iodide in the absence of moisture, oxygen, and light. Molecular str uctural characterization for the cyclic trimers was achieved by H-1, C -13, and P-31 NMR spectroscopy, infrared spectroscopy, elemental micro analysis, and FAB mass spectrometry. These small-molecule reactions we re used as models for the preparation of the corresponding high polyme ric analogues. The synthesis of the poly(metallophosphazene), [NP(OC6H 4R)x-(OC6H4X)2-x]n, where X = H or Br and R = FeCP(CO)2, via the metal -halogen exchange reaction of [NP(OC6H4Br)2]n with n-BuLi at -78-degre es-C, is described. Structural characterization for this polymer was c arried out by solid-state C-13 NMR spectroscopy, KBr infrared spectros copy, and elemental microanalysis. Thermal properties were investigate d via differential scanning calorimetry, thermogravimetric analysis (T GA), and TGA/mass spectrometry. The organometallic-containing polymers showed solid-state paramagnetic behavior. Modification reactions at t he surface interfacial region of cross-linked films of [NP(OC6H4Br)2]n were also investigated. Controlled exposure of these films to lithiat ion and metal-halogen exchange conditions, as described above, allowed the preparation of surface-metalated materials. These surface-metalat ed films were characterized by the use of X-ray microanalysis and scan ning electron microscopy (SEM), transmission electron microscopy (TEM) , contact angle measurements, and attenuated transmission reflectance infrared spectroscopy (ATR-IR).