The coordination chemistry of plutonium(IV) and plutonium(VI) with the complexing agents tetraphenyl and tetra isopropyl imidodiphosphinate (TPIP- and TIPIP-) is reported. Treatment of sodium tetraphenylimidodiphosphinate (NaTPIP) and its related counterpart with peripheral isopropyl groups (NaTIPIP) with [NBu4](2)[Pu-IV(NO3)(6)] yields the respective Pu-IV complexes [Pu(TPIP)(3)(NO3)] and [Pu(TIPIP)(2)(NO3)(2)] + [Pu-IV(TIPIP)(3)(NO3)]. Similarly, the reactions of NaTPIP and NaTIPIP with a Pu(VI) nitrate solution lead to the formation of [PuO2(HTIPIP)(2)(H2O)][NO3](2), which incorporates a protonated bidentate TIPIP-ligand, and [PuO2(TPIP)(HTPIP)(NO3)], where the protonated HTPIP ligand is bound in a monodentate fashion. Finally, a mixed U(VO/Pu(VI) compound, RUO2/PuO2)(TPIP)(HTPIP)(NO3)], is reported. All these actinyl complexes remain in the +VI oxidation state in solution over several weeks. The resultant complexes have been characterized using a combination of X-ray structural studies, NMR, optical, vibrational spectroscopies, and electrospray ionization mass spectrometry. The influence of the R-group (R = phenyl or 'Pr) on the nature of the complex is discussed with the help of DFT studies.