305814-65-7 4546-04-7 EINECS 224-902-0 NSC 203064 Phosphonic acid, (1,4-phenylenebis(methylene))bis-, tetraethyl ester Phosphonic acid, (p-phenylenedimethylene)di-, tetraethyl ester Tetraethyl (1,4-phenylenebis(methylene))bisphosphonate Tetraethyl p-xylylenediphosphonate p-Bis(diethylphosphono)xylene p-Xylylenebis(diethyl phosphonate)