Using NMR Spectroscopy to Evaluate Actinide-Ligand Bond Covalency

Understanding actinide-ligand covalency is at the center of efforts to design new separations schemes for spent nuclear fuel, and thus features considerable practical importance. NMR spectroscopy is a widely available means of measuring 5f covalency that is complementary to more established methods, such optical spectroscopy and XANES. However, its use for this purpose is still in its infancy. Herein, I will discuss our efforts to develop 1H and 13C NMR spectroscopy for the evaluation of An-L covalency in a wide variety of diamagnetic actinide complexes, including thorium allenylidenes and thorium hydrides.