Addition of 1 equiv of Li(Ar(2)nacnac) (Ar(2)nacnac = (2,6-(Pr2C6H3)-Pr-i)NC(Me)CHC(Me)N(2,6-(Pr2C6H3)-Pr-i)) to an Et2O suspension of UO2CI2(THF)(3) generates the uranyl dinner [UO2(Ar(2)nacnac)CI](2) (1) in good yield. A second species can be isolated in low yield from the reaction mixtures of 1, namely [Li(OEt2)(2)][UO2(Ar(2)nacnac)Cl-2] (2). The structures of both 1 and 2 have been confirmed by X-ray crystallography. Complex 1 reacts with Ph3PO to generate UO2(Ar(2)nacnac)CI(Ph3PO) (3). In addition, 1 reacts with AgOTf and either 1 equiv of DPPMO2 or 2 equiv of Ph2MePO to provide [UO2(Ar(2)nacnac)(DPPMO2)[OTf] (4) and [UO2(Ar(2)nacnac)(Ph2MePO)(2)][OTf] (5), respectively. Both 4 and 5 have been fully characterized, including analysis by X-ray crystallography and cyclic voltammetry. Reduction of 4 with Cp2CO provides UO2(Ar(2)nacnac)(CH{Ph2PO}(2)) (6), a uranyl(VI) complex that is generated by the formal loss of H center dot from the DPPMO2 ligand. Labeling studies have been performed in an attempt to elucidate the mechanism of hydrogen loss. In contrast, reduction of 5 with Cp2CO provides UO2(Ar(2)nacnac)(Ph2MePO)(2) (7), a rare example of a uranyl(V) complex. As expected, the solid-state molecular structure of 7 reveals slightly longer U-O(oxo) bond lengths relative to 5. Furthermore, complex 7 can be converted back into 5 by oxidation with AgOTf in toluene.