Ab initio MP2/aug'-cc-pVTZ calculations have been performed to examine the oxidation of P(III) to P(V) in reactions involving FCl and Cl-2 as the oxidizing agents of PH2X molecules, for X = F, Cl, H, NC, and CN. Stable P(III) binary complexes and P(V) molecules, and the transition states which connect these minima exist on all (PH2X + ClF) and (PH2X + Cl-2) potential surfaces. Profiles of binding energies, P-31 chemical shieldings, and EOM-CCSD spin-spin coupling constants J(P-Cl) on these surfaces exhibit similar patterns, with minimum values for transition structures.