Identification of the U(V) complex (C 5 Me 5 ) 2 U V I(NSiMe 3 ) in the reaction of (C 5 Me 5 ) 2 U III I(THF) with N 3 SiMe 3 .

The U(V) imido complex (C 5 Me 5 ) 2 U V I(NSiMe 3 ), 1, was crystallographically characterized from the reaction of (C 5 Me 5 ) 2 U III I(THF) with N 3 SiMe 3 which demonstrates that it can be an intermediate in the reaction which ultimately forms (C 5 Me 5 ) 2 U VI (NSiMe 3 ) 2 and (C 5 Me 5 ) 2 U IV I 2 . U(V) intermediates have been proposed in such reactions, but have not been previously observed. The direct observation of 1 provides insight into the reaction mechanisms of U(III) compounds with azide reagents.