The NMR signals exhibited by the ipso-carbon atoms of a variety of phenylated phosphorus compds., e.g., Ph5P, were found to span over the remarkably wide range of +162 to +117 ppm. Nevertheless, these changes in chem. shifts have little diagnostic value. They are tentatively attributed to a charge-mediated contraction and expansion of the C,P s-bond orbital on one hand and to a s-bond induced deformation of the arom. p-electron cloud on the other. [on SciFinder (R)]