Exchange of an Imido Ligand in Bis(imido) Complexes of Uranium

Addition of B(C₆H₅)₃·H₂O to U(N^tBu)₂I₂(THF)₂ provides U(N^tBu)(O)I₂(THF)₂, a complex with a trans arrangement of the oxo and imido ligands. A DFT study on the Ph₃PO adduct, U(N^tBu)(O)I₂(Ph₃PO)₂, reveals that there are six bonding orbitals in the OUN interaction, much like the bis(imido) NUN interaction. However, the calculations suggest that the multiple bonding in the oxo imido complexes is less covalent than that in the bis(imido) analogues.