eta(2)-Sulfenamido complexes of uranium

Thermally stable eta(2)-sulfenamido complexes of uranium, U(eta(2)-(BuNSPh) -N-t)(4) 1 and UCp2*(eta(2)-(BuNSPh)-N-t)X, X=Cl 2a or Br 2b, have been pre pared by metathetical reactions of LiN(Bu-t)SPh with UCl4/PMe3 and UCp2*Cl- 2, respectively; 2 resists further substitution. Structure determination by X-ray diffraction shows that the bonding of the sulfenamido ligand is anal ogous to that found in its complexes with the early transition metals Ti, Z r, Mo and W. Indeed 1 is closely isostructural with the homoleptic zirconiu m complex, and 2a, 2b are effectively isostructural with ZrCp2(eta(2)-(BuNS Ph)-N-t)X.