Phenylphosphoranyl radicals: are they tetrahedral or trigonal bipyramidal?

Abstract

The e.s.r. spectra of phenylphosphoranyl radicals [Ph_nPX_{3 –n}Y]· show that, depending on the nature of X and Y, these radicals fall into two types in which the unpaired electron is centred mainly on phosphorus or on the aromatic ring.