C−H Bond Activation with Actinides:  The First Example of Intramolecular Ring Bite of a Pentamethylcyclopentadienyl Methyl Group

Thermolysis of (C 5 Me 5 ) 2 U( NAd) 2, 1 (Ad = 1-adamantyl), in benzene or hexane results in the intramolecular C−H bond activation of a methyl group on a pentamethylcyclopentadienyl ligand across the two imido functional groups. The product of this reaction has been spectroscopically and structurally characterized. The activation product is a reduced U(IV) metallocene bis(amide) complex with an N-bound methylene unit derived from the methyl group attached to one amide group. The activation parameters for this process have been determined; the results are consistent with a simple unimolecular process. This is the first example of intramolecular activation of a (C 5 Me 5 ) methyl C−H bond in an actinide complex.