The synthesis, molecular structure, spectroscopic properties and bonding in a complex of dinitrogen with trivalent uranium are described. The molecule has a side-on U-N(2)-U Core which is supported by U -->N(2) pi donation with no significant N(2) --> U bonding. Steric compression between the spectator triamidoamine ligands prevents the uranium atoms from approaching the N(2) ligand at the optimum distance for overlap, and thus the N-N distance is not displaced significantly from that in gaseous dinitrogen.