Abstract
Ligand K-edge X-ray absorption spectroscopy (XAS), a technique that can measure variations in covalent metal-ligand bonding, has rarely been used to assess covalency in complexes containing metal-boron bonds. Here we describe ligand K-edge XAS and TDDFT studies of the Ni dicarbollide complex Ni-(C(2)B(9)H(11))(2) (1) and the Ni-free salt (HNMe(3))-(C(2)B(9)H(12)) (L1). The XAS spectrum for 1 reveals a pre-edge feature indicative of covalent Ni-B bonding, which is corroborated by time-dependent density functional theory (TDDFT) calculations and comparative analysis to L1 and inner-shell electron energy loss spectroscopy (ISEELS) collected on the same Ni complex.