Uranium Hydridoborates: Synthesis, Magnetism, and X-ray/Neutron Diffraction Structures

Abstract

While uranium hydridoborate complexes containing the [BH₄]⁻ moiety have been well-known in the literature for many years, species with functionalized borate centers remained considerably rare. We were now able to prepare several uranium hydridoborates (<b>1–4</b>) with amino-substituted borate moieties with high selectivity by smooth reaction of [Cp*₂UMe₂] (Cp* = C₅Me₅) and [Cp′₂UMe₂] (Cp′ = 1,2,4-<i>t</i>Bu₃C₅H₂) with the aminoborane H₂BN­(SiMe₃)₂. A combination of nuclear magnetic resonance spectroscopy, deuteration experiments, magnetic SQUID measurements, and X-ray/neutron diffraction studies was used to verify the anticipated molecular structures and oxidation states of <b>1–4</b> and helped to establish a linear tridentate coordination mode of the borate anions