Synthesis and structure of small-molecule phosphazene rings bearing fused-ring aryloxy side groups: models for optically useful high polymers

Abstract

A series of cyclic tri- and tetra-metric phosphazenes [NP(OR)2]n(n= 3 or 4), N3P3(OR)Cl5 and N3P3(OR)4Cl2 has been prepared with 1- or 2-naphthyloxy, 1-naphthylmethyloxy, 1-naphthylethyloxy, 9-anthryloxy and 9-phenanthryloxy side groups OR. These syntheses are model processes for the preparation of the corresponding phosphazene high polymers. The small-molecule compounds were characterized by a combination of 31P NMR and mass spectroscopy, elemental analysis and crystal structures of six compounds. Attempts to synthesize the corresponding phosphazene high polymers by similar substitution techniques were, in general, successful, with high-temperature reaction conditions needed to overcome steric hindrance effects.