The reaction between aromatic amines and phosphate radical has been investigated. The reaction is accelerated by electron-releasing substituents and retarded by electron-withdrawing substituents pointing to an electrophilic attack by the PO42xxx radical. σ+para values correlate the effect of substituents well. The rho value for PO42xxx is more positive than that for CO3xxx indicating higher reactivity of phosphate radical towards aromatic amines than the carbonate radical. © 1988.