Perfluorinated Cyclic Phosphazenes.

Abstract

Publisher Summary This chapter discusses properties and reaction chemistry of perfluorinated cyclophosphazenes, with an emphasis on comparing their reactivity with that of the perchlorinated analogs. In contrast to chloro- and bromophosphazenes, for which a variety of synthetic methods have been reported, the only effective way of making fluorophosphazenes is by fluorinating chlorophosphazenes to per-or polyfluorinated derivatives using a variety of fluorinating reagents. Fluorination of chlorophosphazenes, especially the trimeric phosphazene, has been the subject of studies primarily to understand the mechanism and regiospecificity involved in metathetical reactions. The boiling points of the cyclic fluorophosphazenes are similar to those of saturated aliphatic fluorocarbons of comparable molecular weight. Structures of cyclic fluorophosphazenes, especially those of the smaller rings, received increased attention because these data were utilized to support theoretical studies in which participation of phosphorus d orbitals and contraction of d orbitals for effective overlap for π bonding were discussed. Reactions of a variety of monofunctional nucleophiles have been carried out with trimeric perfluorinated phosphazenes.