The (triamidoamine)uranium chloride complex [{U(NN3)(mu-Cl)}(2)] [NN3 = N(CH2CH2NSiMe3)(3)] reacts with alkali metal alkoxides and aryloxides to give a range of complexes [U(NN3)(OR)] (R = Bu-t, t-C4F9, Ph, 2,6-Bu-2(t)-4-MeC6H2). Crystallographic investigations (including the molecular structure of the perfluoro-tert-butoxido derivative [U(NN3)(O-t-C4F9)]), molecular weight determinations, and NMR spectroscopic data are consistent with these molecules being monomeric with a 3-fold symmetric arrangement of the triamidoamine fragment. The;three turquoise ate complexes [U(NN3)(OR)(OR')Li(THF)(n)] (R, R' = Bu-t or Ph), are prepared by reaction of the corresponding uranium alkoxides with lithium phenoxide or tert-butoxide. The complex with R = Ph, R' = Bu-t, n = 1 is shown by X-ray crystallography to have a capped trigonal bipyramidal structure. A lithium atom is incorporated into the ligand sphere by coordination to an amido nitrogen and a tert-butoxido oxygen. The mixed alkoxide ate complex [U(NN3)(OBut)(OPh)Li(THF)] gives only [U(NN3)(OBut)] on heating in vacuo. The one-electron oxidation of these ate complexes to the three neutral pentavalent compounds [U(NN3)(OR)-(OR')] (R, R' = Bu-t or Ph) has been characterized by cyclic voltammetric studies and performed on the chemical scale by reaction with [FeCp2][PF6].