Revisiting the role of octahedral symmetry in the interpretation of spectroscopic properties of [OsF₆]²⁻ and PtF₆ complexes

Abstract

The electronic structure of the [OsF6]2- and PtF6 complexes has been studied by means of CASSCF/NEVPT2 multiconfigurational calculations including, in addition, the spin-orbital coupling, which is very relevant in the...

Relativistic Effects in Ligand Field Theory (I): Optical Properties of d1 Atoms in Oh′ Symmetry

“…The improvement to ξ 5d and Dq when going beyond the strong field approximation and ignoring the secondary relativistic corrections ( p / q = 1) is only 316 cm –1 (3343 cm –1 – 3027 cm –1 ) and 79 cm –1 (2776 cm –1 – 2697 cm –1 ), respectively. This is so because fluoride behaves as a strong field ligand when it coordinates to 5d transition metals, consider as examples PtF 6 and [OsF 6 ] 2– , which are low-spin (breakdown of the Hund rule) rather than high-spin d 4 octahedral complexes. , If the secondary relativistic corrections are taking into account ( p / q = 0.962), the improvement to ξ 5d and Dq results to be barely 57 cm –1 (3343 cm –1 – 3286 cm –1 ) and 15 cm –1 (2776 cm –1 – 2761 cm –1 ), respectively. Hence for the present situation, the ξ 5d and Dq energies obtained from the strong field approximation turns to be in excelent agreement with those obtained by avoiding the strong field approximation but taking into account secondary relativistic corrections.…”