[en] The trivalent uranium compound, (MeC₅H₄)₃U(thf), serves as a one- or two-electron reducing agent towards azides, RN₃. These reactions produce either the uranium(IV) azide, (MeC₅H₄)₃UN₃, or uranium(V) imides, (MeC₅H₄)₃UNR. The role of steric and electronic effects upon this reaction has been investigated using several series of azides. For Me₃XN₃, the imides are produced when X = C or Si, both products are formed when X = Ge, and the azide is produced when X = Sn. For Ph₃XN₃, the azide is produced when X = C or Sn. For Ph_3-xCH₃N₃, the imide is produced when x = 2 and both compounds are produced when x = 1. For substituted phenylazides, RC₆H₄N₃, only the imides are produced. The magnetic properties of uranium diimides, [(MeC₅H₄)₃U]₂(μ-NRN), were investigated. Several uranium(III) amines, (MeC₅H₄)₃U(NH₂R), were produced from (MeC₅H₄)₃U(thf) and RNH₂, and NH₃ was found to be a better ligand towards (MeC₅H₄)₃U than is PMe₃