X-ray absorption near-edge structure of complex compounds (NH4)3RhCl6, K3RuCl6, and Ru(NH3)6Cl3

Abstract
X‐ray absorption spectra of chlorine K edge, ruthenium LIII edge, and rhodium LIII edge from (NH4)3[RhCl6], K3[RuCl6], and [Ru(NH3)6]Cl3 have been measured with a Johann‐type 50 cm bent crystal vacuum spectrograph. The white lines due to the transitions to the incompletely filled antibonding molecular orbital (MO) 2t2g(π*) or nonbonding orbital t2g and the empty antibonding MO 3eg(σ*) for the octahedral complexes have been observed in the Cl K edge, Ru LIII edge, and Rh LIII edge regions. It is found that the two absorption peaks at the Ru LIII edge reflect the ligand‐field effect. An interpretation for experimental results of the Cl K edge and the Ru LIII edge absorption spectra in K3RuCl6 on the basis of the MO scheme leads us to the conclusion that the white lines at the Cl K edge suffer from the effect of core hole.