We present the synthesis, characterization, and one -electron oxidation of two uranium(IV) complexes, coordinated to the cyclen-anchored tetrakis(aryloxide) ligands tetrakishy hydroxybenzyl- 1, 4,7, 1 0 tetraazacyclododecane, ((ArOH)-Ar-R,R)(4)cyclen; R = Bu-t, Me. The new uranium(IV) and (V) complexes exhibit an eight -coordinate, tetragonal ligand environment, effecting exceptional stability of the coordinatively unsaturated uranium compounds. Cyclic voltammetry studies reveal redox events ranging from- tri- to hexavalent species, covering an electrochemical window of similar to 4 V.