there is a form of tautomeric behavior in phosphorus chemistry that can be attributed to the marked tendency to from the phosphoryl group when possible.it became know as early as the beginning of the century that the replacement of the three chlorine atoms of phosphorus trichloride by hydroxy group to from phosphorus acid (h3po3) did not in fact give the expected structure (ho)3 p but instead the dihydroxy compound (ho)2p(o)h in which the hydrogen of one oh group had migrated to phosphorus thus creating the phosphoryl group. similar behavior was observed for the dialkyl esters of phosphorus acid that can result from the reaction of alcohols with pcl3 in the absence of a base