Small-molecule model phosphazenes with para-substituted phenoxy side groups: synthesis, crystal structures and comparisons with corresponding high polymers

Abstract

A series of new cyclic phosphazenes and a linear short-chain phosphazene have been synthesized as models for the preparation of the corresponding phosphazene high polymers. Several of the high polymers were also prepared. The small molecule compounds were characterized by a combination of ³¹P NMR, mass spectrometry and elemental analysis. The crystal and molecular structures of N₃P₃(OC₆H₄R-4)₆(R = CH₃, OH, OPh or OCH₂Ph), N₄P₄(OC₆H₄OPh-4)₈ and OP(OC₆H₄Bu^t-4)₂NP(OC₆H₄ Bu^t-4) were investigated by single-crystal X-ray diffraction techniques. High polymers, [NP(OC₆H₄R-4)₂]_n, (R = OPh, OCH₂Ph or Bu^t), [NP(OC₆H₄CPh₃-4)_1.5Cl_0.5]_n, and [NP(OCH₂C₆H₄OCH₂Ph-4)₂]_n were also prepared and their structures confirmed by a variety of techniques including ¹H and ³¹P NMR spectroscopy, elemental analysis and differential scanning calorimetry.