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(OC6H4But-4)2NP(OC6H4 But-4) were investigated by single-crystal X-ray diffraction techniques. High polymers, [NP(OC6H4R-4)2]n, (R = OPh, OCH2Ph or But), [NP(OC6H4CPh3-4)1.5Cl0.5]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.