Study of Some Pr(III) Complexes: Interelectronic Repulsion, Spin–Orbit Interaction, and Bonding

The values of Slater–Condon (F2, F4, F6) and Racah (E1, E2, E3) interelectronic repulsion and Landé (ζ4f) parameters have been computed from the already observed visible and near-infrared absorption spectra of nineteen Pr(III) complexes. The decrease in F2 values of the complexes as compared to the free ion is greatest among all the parameters and has been explained. The bonding parameter b1/2 = [12(1 − β)]1/2 has also been computed calculating a β value for each complex using the relation β = Fkc / Fkf, where Fkc and Fkf refer to the complex and the free ion, respectively. The relative variation of covalent bonding in the complexes has been discussed.