The preparation and structural elucidation of uranium (VI) complexes and salts of the phosphorus ylides Ph3PCHCOPh, Ph3PC(COMe)(COPh) and Ph3PCHCOOCH2CH3

The reaction in methanol of the phosphorus ylides Ph3PCHCOPh, benzoylmethylenetriphenylphosphorane (BPPY), and Ph3PC(COMe)(COPh), α-acetyl-α-benzoylmethylenetriphenylphosphorane (ABPPY) with UO2(NO3)2 · 6H2O at 273 K leads to the formation of O-coordinated bis(ylide)-uranium (VI) complexes of the type [UO2(ylide)2(NO3)2], whereas the reaction of BPPY and UO2(NO3)2 · 6H2O under reflux in benzene yields the salt [H-BPPY]2+[U2O4(NO3)4(OH)2]2-. The reaction of Ph3PCHCOOCH2CH3, carbethoxymethylenetriphenylphosphorane (EPPY) with UO2(CH3COO)2 · 2H2O produces the salt [H-EPPY]+[UO2(CH3COO)3]−. The structures of the free ylides ABPPY and EPPY are also discussed.

The synthesis of several uranium (VI) complexes and salts of the phosphorous ylides Ph3PCHCOPh, Ph3PC(COMe)(COPh) and Ph3PCHCOOCH2CH3 are reported. All compounds have been fully characterised using spectroscopic techniques and single-crystal X-ray diffraction. The complexes [UO2(Ph3PCHCOPh)2(NO3)2] and [UO2(Ph3PC(COMe)(COPh))2(NO3)2] are the first examples of uranium-ylide complexes in which the uranium metal is present in the VI oxidation state.Figure optionsDownload as PowerPoint slide