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.